I, too, have long been plagued by the sore fact that something is screwy about GTK and tablet sensitivity in GIMP for Windows. Well, after long hours of searching, I found a simple, yet unorthodox way to get the tablet to work.
And to ease your worries, its NOT NOT NOT appending your shortcut to ignore wintab; Actually what you have to do has nothing to do with a shortcut.
Go to START > Run… and get your command prompt.
Type This: “C:\Program Files\GIMP-2.0\bin\gimp-2.0.exe” --use-wintab
There ya go. You have tablet sensitivity. Instead of clicking your shortcut and all that good stuff, just run it from the run command in the start menu. Don’t know why it doesn’t work the other way by messing with the shortcut, but who cares…I can PAINT in GIMP for WINDOWS! WOOOOOO!!!
Forgive my banter is this was previously posted. However it’s such good news for me that I’m all shits and giggles right now.