When I was upgrading hdd on my 60gb PS3 I warped the screw. I used the proper screw driver and the screw stripped on first try. So I put WD40 on swab and slowly put WD40 around screw. I waited about 30 minutes before using a wire cutter to get ahold screw and it finally broke free. I used needle nose pliers ,stripped screw remover, and assortment of screwdrivers. It has come to my attention that Sony has either put the screw in to tight or they're screws are made of clay. Long story short, I think I won't be replacing the blue screw. Edit: I would show everyone picture of screw but, a friend threw it up against a wall. I would put it back anyway.
Probably had some oxidation on the threads, both the screw and the grounding plates are galvanized, since zinc tends to swell badly as it corrodes even trace amounts can jam it in there. I had some trouble the first time with mine too. Edit: there isn't any real reason to replace it. I don't understand why Sony bothered putting one in, a ridge and hole would have done the same thing without the extra part.
Unfortunately, the PS3 has a oddball GPU assembly. It's usual that after 2 or so years of use the thermal compound that does the thermal interface of the GPU core to the heat spreader dry out and cause the GPU core to overheat. The Syscon will detect that the GPU is running HOT and will speed up the fan. While it has no immediate consequences, in long run it causes the BGA solders under the GPU assembly to crack and you will have a "Yellow Light of Death" (YLoD) incident eventually. Only solution (it's difficult to do though) is separate the heat spreader from the GPU body (it's glued on the 4 GDDR chips at the corners with thermal glue) and apply good quality thermal compound to replace the faulty one. Also make sure you replace the white thermal compound on the heatsink side of the chip. Replacing the white compound only is already very likely to help improving the situation. Because the early PS3s use 90nm chips, they heat a LOT and even with proper cooling (as Borman mentions) it may run the fans louder. But it should NEVER spins it's fans faster than 50% at any given moment. If it does, you have thermal issues within it.
There's places on this country that have 105f at summer. You guys are sure having your own "a hell of a summer" though ... >.>