Problem with Photoshop and Tablet Stylus Pressure

[Shachza]

I asked for, and received, a tablet from my family for my birthday a while back.  Now that I'm in a sketching class (Life Drawing for Animation) and I'm watching a classmate develop his skills I thought it would be high time to do the same.  However, Photoshop refuses to cooperate.

Here is what the tablet's software's pressure test looks like when I play around with it.  You can clearly see the lines varying their weight as I apply varying pressure.
http://www.furaffinity.net/view/6321546/

Here is what Photoshop produces when I try and use the tablet:
http://www.furaffinity.net/view/6321550/
The two arrows that I added with my mouse point to two VERY faint and perfectly straight lines; the normal product of me drawing anything with the stylus at any pressure.  It seems to ignore all of the pressure information and squiggles/curves that I try and draw, and it just plots the beginning and end points before drawing a 1 pixel line between them.  The various dots (and dash) are what it gives me if I tap stylus on the pad, so I know it can record varying pressure.

Any ideas on what I'm doing wrong?  I have no idea why it would only record specific parts of the information I'm feeding it when I try and use the stylus.  The stylus' batteries are new as of two days ago, so it's not lack of power.  The actual tablet is a Genius brand MousePen series.

Halp!

[Inumo]

What type of tablet is it? I know that my tablet, a Wacom Bamboo, does that from time to time. I have to close Photoshop and do a full user preferences reset for it to start working properly again. Maybe that'll work for you?

[Shachza]

I followed your advice and I've figured out how to get it to work.  Sort of.

When I first open photoshop I can use the tablet to draw just fine.  However, if I ever touch my mouse, or if I set the stylus down for too long (a couple minutes), or sometimes randomly when I'm not drawing (like when I'm switching colors, or creating new layers, etc...) it will go back to doing what I showed in the first post.  I can fix it by saving and re-opening photoshop, but sometimes I have to do that a couple times a minute if it gets disagreeable while I'm preparing non-brush parts of a drawing.  So incredibly frustrating!

Any ideas how I can get it to work more...  consistently?