Engadget reports that the 
Microsoft’s Tablet PC Edition of Windows XP bug that causes the Tablet Input Panel (TIP) to misbehave to a point where your system can’t use the TIP as an input option is really a pain. 

Right now Microsoft is reportedly telling people to reboot daily.  Nice … but I still have the problem and reboot at least three times a day (leave home in the morning, leave work in the evening, shutdown over night) … this on a Tablet with 1.5-GBs of RAM.

I’ve had to revert to carrying around 3×5 index cards between meetings as a backup to make sure I can capture something if the TIP stops working.