If you happen to have the .NET Framework 2.0 pre-release installed on a Tablet PC and you've noticed reliability and/or stability problems using the Microsoft Ink functionality on your Tablet, Microsoft has released an update to fix some compatibility problems:

"Compatibility issues (events not firing, classes being disfunctional) with CLR2.0 have been found in Windows XP SP1/SP2 versions of Microsoft.Ink.dll on Tablet PCs. Since this dll is a system file on these configurations, they require update through Windows Update."

You can download and install the update here.