Case Summary: Important Web+Center 3.5 to 4.0 Upgrade Fix ---Case form displays duplicate categories after upgrade AND DoTCaseform.asp gives CInt() error in line 880.
Web+Center 4.0 Production
After upgrading from version 3.5 to 4.0 the "Case" form shows multiple instances of the same category and the items in the category are shown to be split between the two instances.
To fix this problem, the category lists must be re-configured using the manage category list option now by going to: [Administration -> System Configuration Menu -> Manage Category List] and selecting a category displayed in the "Edit Category List" press the Edit button. There is no need to change any information just press continue and go back to the "Edit Category List" to select another category. You must do this for all your lists. Once they have all been touched you should solve any DoTCaseform.asp modules issues.
After performing these steps the "Case" form displayed as expected and worked properly.