Well I got a brand new GS and when I removed the heatsink I also got a bit of residue from the thermal pad left on them.
I guess it's just a matter how hard the little chinese kids tighten the screws

Believe it or not but there was blood on my units :/
Well still is lol.
Also, after some testing here, it seems that these "mods" are somewhat bad. As far as I know, we get paid per share. I'm hashing away at ~530Kh/s (Running at 1213Mhz with 0 HW), but after 1 hour my machine that is hashing at 400Kh/s (900Mhz with 0 HW) is making just a few shares bellow the OC one (Like less than 5). I'm not even sure if I'm going to mod my other miners (I could be wrong). Anyone else who modded their units are running into this problem?
Thanks!