Here are the steps to reproduce this issue (keep in mind that we are running Revit 64 bit on Vista 64 bit):
- Create a schedule that includes Type Properties that you can directly modify.
- Open the schedule.
- Modify the Type Property.
- Using your mouse, click the 'x' or Close button in the top right corner of the schedule window.
- Revit will provide you with a dialog box - Click 'OK'.
- Revit crashes.
See if you can reproduce this.
It would be wise to Save your project before trying!