It's a tall order to try and reason out that problem purely from the description. Replicating the behaviour outside of your setup would be near impossible. However, there are a few question you could try to answer that may shed some light.

You say that "I have run this script many times on a few different machines and have found that the problem only occurs in one directory." and "The directory in question is a shared directory".

Does that mean that it is the same directory on the same machine that is being shared to all of your test machines via the network? If so

• Is it the only directory you are accessing as a share?
• Is it the only share you are accessing on that machine?
• Does the problem go away of you run the program on that machine?

Essentially, you need to try and isolate what it is that is different about that directory or machine from the other directories. For example; is that machine running a different (version of the) OS? Have you checked the event log (assuming its Win) on that machine? Maybe there is a problem with the browser deamon, or the the filesystem that has errors which are slowing things down.

You might even look for things like the connection speed of the lan segment to which the shared directory is connected. If the machine in question was using a 4MB NIC or a was connected through a slow or overloaded router it might produce some slow down. A few point to point tests of network speed from the command line to the problem share should determine this.

Is the machine where the directory in question in the same domain as the test machines? I've seen a situation in the past where accounts in one domain accessing a machine in a different domain were authorised to do so, but the process of authentication required a tortuous negotiation path between several domain controllers each time. Worth a mention.

A few ideas that spring to mind. As a first pass, I would probably replicate the problem directory to a different machine and redirect the share and see if that effects a difference. It's all about trying to isolate the differences.

Good luck.