When using custom widgets and saving them, they get saved under the Filestorage folder. In some situations, the filestorage folder may need to be located outside the default location, such as on a UNC share on the network. The issue may arise that the widgets’ javascript events no longer fire.
The solution would be to disable Dynamic Compression and Static Compression.
Steps to disable compression:
http://technet.microsoft.com/en-us/library/ff730244.aspx
This solution only applies to IIS7.
A Feb hotfix for 2012 is scheduled to resolve this issue.