"Cannot find new threads" on Fedora 9, but not on CentOS 5 (?)

[Andrew Lofthouse <loftyhauser at gmail dot com>]

I'm trying to debug an application that throws a SEGFAULT in a shared 
library.  On Fedora 9 (and on Ubuntu 8.04), I get the following error:

[Thread debugging using libthread_db enabled]
Error while reading shared library symbols:
Cannot find new threads: generic error
Cannot find new threads: generic error

However, when using CentOS 5, the debugging session seems to work fine 
and gives the following output:

[Detaching after fork from child process 1973]
[Detaching after fork from child process 1992]
[Detaching after fork from child process 2004]

Program received signal SIGSEGV, Segmentation fault.

etc, etc--basically gdb works and tells me where the segmentation fault is.

So, I know that Fedora 9/Ubuntu 8.04 use gdb version 6.8, while CentOS 5 
uses version 6.5.  Why can an earlier version of gdb work fine, while 
the later version doesn't work?  What can I do so that the later version 
works?

Thanks,

Andrew L.