well haven't managed to fix it...but from reading all the posts everywhere i could find it seems that since this *** glibc detected *** is some sort of internal glibc checking function it might actually not be a bug.
It seems to be triggered when a php script on apache (php running as cgi in this case) goes in to loop (header(location:....)) glibc detects this as a corrupted double-linked list.
or then again the loop may be occuring because of this bug.
don't really know
...have to take the time and test the whole php site i guess.
but if anyone knows if a php redirect loop could be the reason for this internal check to fail feel free to confirm it and make me feel better