Our company is running a 3 server web farm that connects to a single file server and database server.  After upgrading to 4.4.1 we are experiencing a countless number of errors regarding caching and it has brought our entire operation to a standstill.  Here is the error:

System.IO.IOException: The process cannot access the file 'D:\Domains\polk.agsportal.com\Portals\_default\Cache\VGFiUGVybWlzc2lvbnMw.resources' because it is being used by another process. at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) at System.IO.File.Delete(String path) at DotNetNuke.Services.Cache.FileBasedCachingProvider.FBCachingProvider.DeleteCacheFile(String FileName) at DotNetNuke.Services.Cache.FileBasedCachingProvider.FBCachingProvider.GetPersistentCacheItem(String CacheKey, Type objType) at DotNetNuke.Security.Permissions.TabPermissionController.GetTabPermissionsDictionary(Int32 PortalId) at DotNetNuke.Security.Permissions.TabPermissionController.GetTabPermissionsCollectionByTabID(Int32 TabID, Int32 PortalId) at DotNetNuke.Entities.Tabs.TabController.FillTabInfo(IDataReader dr, Boolean CheckForOpenDataReader) at DotNetNuke.Entities.Tabs.TabController.FillTabInfoDictionary(IDataReader dr)

Almost every page is failing.  If I turn off caching altogether the error goes away, but then it puts an intense load on our database server and the site is not usable that way either.  This is a major issue for us and I need someone on the core team or who is aware of this issue to help us out as soon as possible.  Our web farm was running just fine under 4.3.6 and this error never popped up until after we upgraded to 4.4.1.  This is happening on all of our sites now.

If anyone can help it would be greatly appreciated.  Our entire team is stumped at this point and our customers are growing increasingly angry at us.  Please help!