Please tell us this:
Are you using Windows, Linux or Mac?
Does your wacom bamboo works fine with Inkscape or Gimp?
At Synfig Studio Device Settings dialog, do you have the stylus screen enabled or window enabled?
Can you double check that you ONLY have one device enabled from your devices list (it has to be the stylus)
Winodws 7 64 bit is my OS, I haven't tried using GIMP and I've never hear of inkscape, the only drawing program I've used/own is the Sai painting program (It's a corel like program from Japan)
On the device settings dialog, it lists three devices I can keep active, which are:
Wacom Puck Transducer (I can set it to be disabled, window or screen)
Pressure stylus (same options)
Pressure eraser (Same options)
Disabling any of those removes all the functionality of my tablet. I've been playing around with the settings and I'm stumped.