Doesn't seem to do anything on my Bold. Just get an empty white screen with "Blips" in the title bar. Twiddling options does nothing. Had it running for about 20 minutes yesterday evening as I travelled around a bit.
Other apps have no problem accessing the GPS (Google Maps, BB Maps, Blackstar, etc).
EDIT 27/11/09
Now that I've updated to the 1.4 version of the Blipper everything's working on my Bold.
There is a certain addictive quality to recording all the coverage, uploading and then waiting with bated breath for coverage maps to update so you can trace all your journeys and trips!
The only downside is that there aren't too many people updating in the UK yet, so you'll be able to literally trace my home, workplace and hobbies to within a few metres very soon!