>Couple of things to check that may or may not help:
>
>In Solution Properties :
>In "Debug Source Files" check which locations are (and are not) searched for source files
>
>In Tools/Options/Debugging:
>in 'General' make sure 'Enable just my code' is *not* checked. Also try with 'Require source files to exactly match.... ' unchecked.
>Check settings in 'Symbols'

Thanks Viv,

that got me going again. I removed a few paths from the "not searched" locations, then when I was prompted to locate the source code from an MM.Net class I searched for that class and found it and everything seems OK now.

Hopefully now I'll be able to work out what's wrong with my code :)