The pen pressure does not update during the stroke. E.g. when using it on size and strength those stay at the value recorded at the start of the stroke even when pressure is altered along the way.
pressure sensitivity is on for brush size. Stroke is started with very low pressure and pressure is increased along the stroke. The brush size stays at the same small size for the entire stroke.
The problem does not occur during texture painting (either in 3d view or image editor) or in other applications.
Blender version is trunk 53455, 64bit. encountered the problem earlier too.
Tablet is Wacom Intuos 3 with latest drivers (nov 2012).
Windows 7 64 bit
I just did a couple of tests with 2.65 r52860:
the issue only appears when using custom keybindings imported from 2.64, 2.63 or other versions.
I guess I'll have to redo all those from factory settings.
I have encountered problems with custom shortcuts earlier when changing versions with keybindings becoming mixed up with default settings and various assignment conflicts. I guess the issue lies with changes in the keybindings and settings, although strange that something which has no settings available at all is being affected.