This is a bit complicated to explain so I will tell you the steps to create the problem and see if others can recreate it and help to fix it.
1. Create a page
2. In Ultimate TinyMCE create a table 8 colums by 20 rows
3. Select colum 6 and 7 in row 4 down to row 10 so you have a box 2 colums by 7 rows
4. Then from the tables dropdown menu select merge cells.
5. Place an image 300w x 600h in the merge cells.
6. Then in row 4 select colum 1 to 4 and merge the cells
7. Repeat step 6. For rows 6, 8 and 10.
8. In row 4 colum 1 which now spans 4 colums put one word eg TinyMCE and give the merged cells a background color.
9. Then in rows 6, 8 and 10 add a paragraph of text so that in total you have more text than the image is high.
10. Then save the page and view the page in a browser.
If you get the same problem in the browser row 4 will match the height of the image. Strange huh? Any one know how to stop this from happening?