Using TF3, latest version, I can select a track point, but can't delete any. Running on MS Vista Home Deluxe. This happens in several different GPX files.
Just tried it on an XP machine, and I can delete trackpoints on that machine in TF3.0.
The Vista system is using an Nvidia Graphics card with the latest non-beta vista drivers from Nvidia. 3.0 GB RAM.
EDIT - Problem fixed with 3.05 beta. Never mind...