1. I don't see the "-" buttons - see the screen shot. I checked the style sheet and the referenced file, url(../../img/ico/minus-button.png ), does not exist.
2. Add fq seems to work fine.
3. When I had 4 fq's (111, 222, 333, 444) and I clicked where the "-" button should be for the 222 row, it in fact deleted the 222 row, but also deleted the 444 row! Leaving the state shown in the screen shot.
4. If I fill in a new row/fq and hit Enter, everything is fine, but... then there is no "-" button for that new row. Or maybe that's just because the image file is missing.
You can see the actual fq's in the XML query response.
This is Google Chrome.
Local build of trunk plus the patch.