\\SERVER\Share is not accessible. you might not have permission to use this network resource. not enough server storage is available to process....

I've had this nagging problem for a week now on our domain. The shared folder is actually an external USB drive.

Have tried per Microsoft's instructions to increase the IRPStackSize to no avail.
Also tried removing computer from domain and re-adding - no luck.

I then thought back to what I had done to the computer in the past week.

I'd remotely deployed Acronis True Image server and Symantec Corporate Anti-virus.

Out of curiousity, I tired removing the Acronis True Image server and rebooting.

Guess what? The problem went away! Go figure!