If you're having an issue with trying to figure out why your ViewStates are so large, check to see if you're storing any enum values inside the ViewState. ASP.Net stores each enum type's fully qualified assembly name inside the ViewState, which really bulks up the ViewState length.

An easy way to get around this is to convert the enum values to their basic value types before storing them to ViewState.

Windows 7 x64 only comes with a 64 bit version of iexpress.exe. This version only creates package files that are 64 bit. Keep this in mind if you need to create a package that needs to work on 32 bit operating systems!