This issue seems to suggest that you may not have run the SL VBTools/SDK upgrade utility.
Have you tried screen upgrade through that SL upgrade?
If not, in my SL2011 environment it is located at C:\Program Files (x86)\Microsoft Dynamics\SL\Applications\VT\VB 2005 Code Converter\SolomonSDKConversionUI.exe.
Using this application you have to convert it properly.
Hope this Helps
Thanks & Regards