IE9: Problems while inserting nested tables

[j.swiderski]

Founded when reproducing #8675

1. Clear editor contents or place cursor at the end of contents
2. Insert table
3. Cursor is clicking inside 1st table cell
4. Insert another table or E.g. image/iframe/flash

Result: Table or other element will be inserted in last cell.

Reproducible from CKEditor 3.6.1 rev [7004]

Workaround: To insert nested table in first cell you have to click it first.