A consulting client of mine ran across a nasty repeatable InDesign bug today. I did some further testing and refined the bug down to the following essentials:
1. Create a new document in InDesign CS3 5.0.4 Mac or Windows.
2. Create a new text frame, and choose Table > Insert Table.
3. Create a table with 3 body rows and 2 columns.
4. Horizontally merge the two cells of the first row of the table.
5. Vertically merge the two cells in the bottom-left corner of the table.
6. Now, here's where it gets interesting: click inside the vertically merged cell in the bottom-left corner of the table, and drag straight up, as if you were trying to select the cells above the merged cell also. InDesign CS3 will immediately crash.
This DOESN'T cause a crash in CS4 (or CS2 for that matter). So I assume it's a known bug that was squashed in CS4.
So, avoid dragging from the bottom up in tables, and you won't encounter this bug. Top-down dragging doesn't cause a problem.