Labels field in Edit mode spans across the whole page, when the browser window is resized to smaller size.

1. View an issue.
2. Edit the Labels field to have a lot of labels in it ( close to 15 labels of more than 6 characters. )
3. Click on the field to Edit it.
4. Add more labels.
5. Re-size the window.

Video Capture: http://screencast.com/t/NTMe08fU

Labels field spans across the whole page, instead of resizing itself.
I noticed this issue only with Labels Field, couple of other fields like Versions, Components, Environment, Custom text fields seem to span well.