Hi!
my old system: athlon-tbird 1400 MHz, via kt266, 2x256 MB PC133 SDRAM (brand)
I had the same problem with qt, tetex, mysql (for some weird reason i did not get any errors compiling glibc + gcc or even xfree) and some other packages.
After running memtest86 it threw errors in test 5 and 8 (repetitive memmoves, according to the documentation on their website (
http://www.memtest86.com) it's the test which is supposed to strain the memory the most (and some interesting comment about mostly athlon systems failing these two tests only).
So I suspected the SDRAMs at first - but then we tested them in two other boxes - they ran fine. I suspected some heat problem with the cpu, so i renewed the heatsink compound (after cleaning thoroughly) - no improvement.
I flashed my bios to an elder version - nothing.
The solution turned up some 2 days later, when the memory faults increased dramatically; the reason: faulty capacitators on the motherboard.
My advice to you: it hasn't got to be the memory, just take a close look at all the capacitators on your board. If they bulge out or eaven leak, you should try to get an RMA. take a look at
http://www.ttiinc.com/MarketEye/Aluminum_Cap_Issue.asp
or, if you understand german
http://www.heise.de/newsticker/result.x ... densatoren
these are just two hits taken from a quick google search.
(sorry for my english, feel free to correct me.)
(EDIT: cleared up a bit)
P.S.:Well, my MoBo (may it rest in pieces) gave up after some more tests - now I had the excuse to go buy a new System. Now working with an AMD XP 3000+ (Barton, 200 MHz FSB) =) the gentoo experience improved
dramatically.

To all gentoo devs (and the community): you rock!
(trying to contribute... nothing yet

)