X200 Stylus pen wont work when using as a tablet

[liliggyracin]

I have an X200 7449-88U and if I have it sitting up like a Normal Laptop I can use the pen just fine. If I flip the monitor and set it down and try to use it as a tablet the pen quits working. Have installed everything I can find and am hoping you all have a little better Idea. We have a very limited number of tablets and this is only happening to 1 out of the 5 we have. All of the others are fine. Currently running Windows XP Tablet Edition SP3 is installed. Any ideas?