VS2005 isn't using the Windows CE Tools\wce420 directories, it has the PPC and SP 03 SDK's under the following directory: C:\Program Files\Microsoft Visual Studio 8\SmartDevices\SDK\
Also VS2005 is using it's own version of the MFC\ATL libraries under C:\Program Files\Microsoft Visual Studio 8\VC\ce\atlmfc, and these versions assume hexidecimal values are passed in.
So I believe that the fact that it changed from Decimal to Hexidecimal is fine as all the files that VS2005 are including should have the correct representation. Assuming you are using the built in SDK's and ATL\MFC's.
What problems are you seeing exactly