Moepower,
We ran into similar problem. This is caused by the application of the Microsoft KB824141 update to the Windows 2000 system. To our knowledge Brio currently do not have a patch for the problem. Upgrading to Brio version 6.6.4.40 or uninstalling the update patch will solve the problem.
If you can't convince your sys admin to do either here are some work around. Use the caps lock key rather than the shift key for letters and using a text editor to capture the text and cut and paste into the text box. To get double quotes and other special characters that can't be reached by CAP LOCK, type the characters in a Word document and cut and paste into the Brio document.
Hope that helps.