Thanks I will look at sysinternals to see what is happening.
The netware/OES driver is simply a network shell that provides extended permissions, rights, etc to that server.
As for the decompression, files are compressed on the netware servers. It is a process that runs in the background to save space for infrequently used files. When a backup program tries to use a file that has not been opened in a while, the netware server needs to decompress the file. It may be that if you call the file open and the open times out, this may be the cause.
Should we test this as a CFS share versus a mapped drive?