I've been having trouble with non-C++ files in visual studio. Specifically, I load them up and then right click on their tab and select "New Vertical Tab Group". My file will show up on the second pane alright but as soon as I click iinside the source file VS hangs within a second or two.
today it was a file with the .vp1 extension. its contents were shader assembly a-la ARB VP1. The other day it was happening with a file with the .idl extension (but was a different IDL than MS's).
Also, my machine is dual-monitor dual-core and I have visual studio stretched across both monitors. I have a second machine that is single-monitor single-core that does not exhibit these problems. The problem free machine is running 1446.