Please reorder columns to be in the following order by the fault:
- Assigned To
- Target Version
The idea behind this is the following (I'm judging by my work experience):
- ID is first for obvious reasons
- Summary goes next to ID as it is the most important column
- Priority is the field the user will sort rows by most often. Even more, after sorting the rows it is still important to see what priority the bug exactly has, so it must stand next to Summary
- Status is also used as sort criteria, although rather rarely (it used as filter mostly), so it goes next to Priority.
- In most cases, Assigned To, Category, Target Version and Tracker are used as filters (with single value specified) and there's no need to spend much time looking at them or sorting by them. They all go in the middle. Still, Assigned is sometimes used as sort criteria, so it goes first amongst them.
- Updated is used as sort criteria very often. However, user almost never needs to see exact date (row order itself is sufficient), so we can place it as last so it is very easy to find.