X86_64 apps segfaults

Question

I'm seeing a very strange problems on my macs running 10.5 (an iMac and MacBook pro, booth from mid 2007, Core2):
All x86_64 binaries segfaults if I provide too many command line arguments to them.
I've only managed to reproduce it on my 2 machines, and I've tried about 5 other Core2 machines running 10.5. I don't think I'm the only one seeing this problem though. This issue with netbeans seems to be the same for example: http://lists.apple.com/archives/Java-dev/2008/Sep/msg00007.html
Some observations:
Both my machines have been running 10.4 earlier and are upgraded (now running 10.5.6)
All other machines I've tried have only been running 10.5
All x86_64 binaries (Chess.app, java,... ) crash if I provide about 30 arguements. Even very simple apps like this one:
$ echo "int main() {return 0;}" >foo.c
$ gcc -m64 foo.c -o foo
$ ./foo 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
$ ./foo 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Segmentation fault
The number of arguments a program can handle seems dependent on the number of environment variables. If I add a dummy variables like "export FOO=1", I can provide more argument before getting a segfault etc.
I'm not getting anything that is useful to me from gdb. The crash happens before main().
There's no problem running as root, but any other user account has the problem, even newly created ones.
If I install 10.5 (from scratch or by upgrading 10.4) on another disk I see no problems on my machines.
The components involved (libSystem, the kernel, dyld) seems to have been replaced in the 10.5.6 upgrade, so they must be up to date. Any other file or setting somewhere to look for?
Does anybody have any ideas of where to look for errors?
Virus? Root-kit?
Can anybody else reproduce this problem? Just try running java with 30 or so arguments in the terminal..
Any ideas would be appreciated.

Answer 1

64-bit foo works fine in 10.5.4. I never upgrade right away. I heard about problems in 10.5.5 and held off. Now 10.5.6 is out and it has problems too. I will check again in mid-January.