Folders with strange names appear

A customer of mine keeps getting empty folders created on their server with strange folder names such as 17a1b0558b7b43c9.

They are running a database built on Pervasive and have Iomega quicksync mirroring to an external hard drive.

These can usually be deleted although sometimes there is a message access denied.
What is causing these folders to appear?, anybody!!
Thanks in advance