I've installed Build 729. Now, during a build, VS silently exits (without any exception or message). Not every time, but about once an hour. This seems to relate to R# Build 729, since it didn't happen before.
When I have no code windows open, it doesn't seem to happen. Maybe it has to do with the parser, trying to parse something while building?
Note that I have lots of LINQ constructs in my code which aren't supported yet by R#.