The current 10.2.0 driver used by applications needing passwordless (wallet) Oracle database access has a bug which prevents it from connecting to Oracle from a client machine which has been up for more than 200 days (32-bit linux kernel version 2.6) or 248 days (32-bit linux kernel version 2.4)
A patched version of the client tools has been made available which fixes this problem.
We have a central configuration script (actually 2, one for each of unix sh and csh) which requires a 1-line change to point everything to the new driver.
Backing out the change is only a matter of restoring the original pointer.
I've tested both clients on both 32-bit and 64-bit linux machines and the results are consistent.