Please describe the problem:
There's problem with the drop-down button that appears when you select a cell with "in a list" validation and "in-cell drop-down" enabled. When you apply these settings to a range of cells, and select a cell from that range, the button appears next to that cell. But then if you select another cell from the range, the button is still next to previously selected cell.

I've found that this happens only if these cells have the same background color (possibly entire formatting), and if you apply the settings to each cell separately, the problem doesn't show up.


Steps to reproduce:
1. Start with an empty sheet
2. Select any range of cells
3. In the formatting dialog set the validation mode to "in a list" and turn "in cell drop-down" on
4. Select a single cell from the range
5. Select any other cell from that range


Actual results:
You should see that the drop-down button is still next to the cell you've selected first, not next to the current one.

Expected results:
The drop-down button should be always next to the currently selected cell.

Does this happen every time?
Yes, at least for me (I didn't test it on other machines).

Other information:
I don't know the internals that lay behind Gnumeric, but it appears to me that each time you apply the same formatting to range of cells, then some (single) object containing the format is created. And if you set the same formatting to different cells separately, then it's contained in separate objects. So it could be possible that "drop-down" button's position updates only when the object containing the format of selected cell changes, not the cell itself. I hope this info will help to locate and fix the bug.