Well, to me it seems all your problems started when you started using glass fuses. They are pure crap. I believe they only go up to 80A, and if you try running amperage through them close to their limitation, they simply melt slowly and as their composition changes the resistance starts to build in that fuse, and it becomes the weakest link in your current flow, meanwhile due to resistance heat builds up, which starts to melt the crappy quality metal around it which is your distribution block. That is most likely your problem. I do not buy crappy ground for a minute. People who use glass fuses, and run them hard, should replace them regularly as maintenance. I refuse to use that crap, period. Once you go into a little bit more power, and start pushing your system, these fuses do not hold up. Try something different. I've melted a good share of those fuses years ago, until I learned not to use them at all, and my problems vanished. I have been using a capacitor as a distribution block for years now. Some people use breakers back there. Fuses do not even blow when their rated current is going through them. Depending on how much over, they hold up anywhere from minutes to hours, in the meantime deteriorating as it happens. For example, and do not quote me on technicality, they even deteriorate when there is 60 amps going through 80A fuse, and as their physical composition changes over time, you're slowly getting yourself into what you're describing, and if you got good ears, and know what to listen for, and know how your system should sound, you will know that the sound is night and day different, especially bass will be lacking and will have more distortion. And when you put a fresh fuse and distribution block in there, your system will sound as if it had a tune-up, until this crap happens again, and you're back where you started with melted garbage. Do not use this stuff. You will keep replacing it.

So, the problem could be that you were using a low amperage fuse for what your amps were pulling, and it was very close in fact, which is a big problem for glass type fuses. This is my guess, cause I do not have the info of all the digits. People do that when they falsely assume, that the fuse should be close to what amp is pulling. It has nothing to do with that. The fuse is there to protect the wire, not the amp, and most people use 4 gauge back there, and should be using 125-150A fuse back there, if thats the case, unless you know for a fact, you will no way be pulling amperage close to the fuse's rating, as you will be killing that fuse slowly. ANL by design has no such flaws, only the crappy glass.

^^^ Oh and when that happens, distribution blocks suffer the same demise, and become more resistive, so even if the fuse is melted, but there is no visible damage to the block, you can bet your ass, the block had suffered internal composition damage, and is not longer the same conductor. The whole distribution block with glass fusing is a bad idea, unless like I said you're not running the system hard enough to get yourself into the danger area. So, if your block suffered damage before, and you kept loading it with bigger fuses, the block is the one causing most heat at this time, and in turn assists in melting your newer bigger fuse, and it does not blow, but just melts away, and goes bad. So, as you can see nothing but vicious circle of problems.

like sasha said, the problem lies in your fusing, or lack there of.

That was my question too, it seems if it was the ground wire, I would have had a problem near there, or at least not in the dist. block. Yes it is (was) a fused block, it had been installed, untouched for a year and 8 months and it was fine, nothing was different when it went. So maybe the fuses just rattled there way loose until they were loose enough to create resistance??

Sasha, I didn't have glass fuses before, sorry if I implied that by accident in some way. However before reading your post I just bought a new block on eBay which uses glass fuses (TLWFDB4-AGU) so that sucks. I'm doubting the ground wire now too because as Rrrrolla mentioned earlier, shouldn't it have melted at the ground wire or somewhere near there if that was the issue??

My previous block did have ANL fuses, and the block had been there for a year and 8 months untouched/unchanged with out any problem, and nothing was new when it melted. So I'm wondering if maybe over the time the fuses just rattled loose (or something rattled loose) enough to create resistance?

You mentioned hearing a difference in the sound, I thought it was just me, but in the last 3-4 months it seemed like my speakers would distort at lower volume then usual. Could be the speakers too I guess (they are nothing special Clarions), but maybe it was this. My sub box has a leak in the seam so I wouldn't be able to tell if the bass was distorted or not because the box makes it sound like it is anyways.

So now that I've bought this pos dist. block, what can I do to maximize its life/quality? I don't mind replacing fuses every so often, they are alot cheaper then a new block. Anything else, and what size fuses would you recommend then?? My fuses on my amps add up to 60 each...

I would recommend what I do. Drop the distribution block idea, and get yourself a cap, and run unfused wires from it to amps if they come with own fusing. Works for me. Some people of course will say caps are useless, but I disagree, and you'll be killing more than one bird here with one stone.

I do have a 1 Farad Phoenix Gold Cap setup right now close to the amps so I could do that, I'm glad to hear theres at least one other person out there that agrees caps are worthwhile :). So that would be just as safe as using a dist. block (The amps do have their own fuses)??

You're good to go!!! :D

caps suck:p
try it that way, I agree glass fuses are !

It is still wise to upgrade your ground. If the fuse is under-rated, it could be the more significant bottle neck, however, if your ground is under-rated also, it too will be a bottle neck.
Are you certain that your ground was not damaged in some way that you can't see?
Go to crappy tire - you can get pre-assembled ground wires with the battery terminal and ground ring in sizes up to 18" of 0 awg wire. For $20ish everything is ready to roll for you.