VS2010 loses breakpoint hits on upgrade from VS2008

I develop some C# Add-Ins for the Sparx Systems Enterprise Architect UML modelling product. The Add-In was being developed under VS2008 and all was fine. I thought I'd upgrade to VS2010 and the upgrade appeared to work without error (or as far as can see any substantive warnings). However, I can't trigger any breakpoints under VS2010. I can set the开发者_运维知识库m but when the code runs under the IDE, the code doesn't stop at the breakpoint.

The PDB files are being created and the source and binaries are in synch. I found some references on the net (and in Stack Overflow) to issues with breakpints and web development, but I'm just developing COM aware Add-Ins with no fancy stuff. I tried some of those solutions "on spec" to no avail.

Anyone got any ideas why the upgrade has resulted in this?

TIA, Paolo

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I had the exact same issue a couple months ago with breakpoints not stopping. I ultimately installed the service pack like @Hans Passant mentioned and it fixed my issues. I've also read that reinstalling VS2010 will fix it, but I think you should just go for the service pack.