I had this problem with VS2010, although ReSharper was never installed in VS2010. However, ReSharper was installed in VS2008, and the VS2010 installation copied the Intellisense settings in the registry from the VS2008 installation.
To fix the problem without buying a ReSharper version compatible with VS2010, to switch Intellisense, I had to change the following registry entries.
[HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\10.0\Text Editor\CSharp] "Auto List Members"=dword:00000001 "Auto List Params"=dword:00000001
Before my editing, both of them read 00000000
This enabled VS2010 again to provide intellisense.
iankb
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