Random errors: what can cause them

Not mapped network drives:
An old problem that you should better know about: under w98, if you do intensive work on a non mapped drive (i.e. using the UNC notation \\MachineName\...) you will in some cases get a crash...

It's unpredictable and the only solution I found to solve that problem was to temporary map that network location to a letter (generally starting at Z), and then unmap it at the end of the process... All this automatically in the code, of course, not by hand...

You should also know that sometime it's impossible to unmap the network drive at the end of the process... It looks like the system is still trying to process everything that was requested and is currently in the disk/system cache, and therefore cannot remove the mapping.

In your code, it's therefore a good idea to check if a mapping already exists for your network location (left from the last time you run that process by example).