File unlock delay

I am having problems with ‘write’ permission on files and folders (on a network drive).  Not always, but many times a day, I will attempt to open a SW file from a Windows Explorer window and get the message that the "file is in use, do you want to open a copy.  Yes/No."  If I try 3 or 4 times, or wait ~20-30 seconds, the file will then open.  The same thing happens with Folders.  With all files closed in SW, I can not rename a folder, even from a different computer, without closing SW.

My box:

Win 7

SW2011 sp2.0

No PDM

Server:

2003 r2

SW License server

My account is a Domain Admin and owner of the SW files location, so there shouldn't be any authentication issues.

SolidworksGeneral