I've installed ReSharper 5 on two installations of Visual Studio 2010 Professional. In both cases, ReSharper claims it has installed successfully - but Visual Studio doesn't recognize the extension. It doesn't show up in the Extensions Manager, doesn't appear in Help - About - Installed products, and can't be found anywhere else in the environment.
I've tried install / uninstall of both Visual Studio and ReSharper, computer restarts, etc. Both machines have Visual Studio 2008 and ReSharper 5 works fine in these IDEs, and both machines are running Windows 7.
I've found other people online with this issue, but no solutions. Anyone know how to fix this?