Visual Studio needs to make non-functional changes to this project

Question

I opened a C# project that was created in VS 2010 SP, with VS 2012. A one-way conversion window appeared where I proceeded with the conversion.

Upon completion I got

Answer 1

I'm unsure as to why exactly this happens but I found that after first opening a VS2010 SharePoint 2010 project in VS2012 amongst other changes the following nodes were added to the .csproj file:

SharePointCustomization
15.0
0
blah\blah\blah
4.0

I found that if I manually edited the csproj file and removed the following three nodes the next time I opened the project no upgrade logs opened and the issue was resolved:

0
blah\blah\blah
4.0