Photoshop + Wacom error (I can only use the eyedropper tool)

I've been using my wacom intuos to draw on photoshop for some weeks now, but something strange started happening out of nowhere:

Whenever I approach the wacom pen to the wacom tablet while using photoshop, the cursor automatically become the eyedropper tool, and that's the only thing that I can do... The tool I was using continues to be the one selected, but it is as if it was overwritten by the wacom.

If i touch the mousepad, the icon goes back to the original one and I can use whatever is selected, but if I try to use the pen again, it becomes the eyedropper all over again. 

I tried starting a new file, resetting the tablet settings, etc, but nothing seems to work. Does anyone have an idea of what could be going on?