MapObjects 2.2 was designed, tested, and supported for use with Visual Studio .NET (from 2002), which uses the .NET Framework v1.0. Unfortunately, it is not supported for use with Visual Studio 2005, which uses the .NET Framework v2.0. It may just work, but we have not tested it. For one, the MapObjects installer only knows how to look for the version 1.0 GAC, so at a minimum, you would have to do part of the installation manually, depending on how comfortable you are with modifying the development environment and the .NET framework.
Even the most recent version of MapObjects-Windows Edition, version 2.4 does not support Visual Studio 2005.
It is unfornuate that ESRI will end MapObjects Supports soon and discontinue the product.