Action column in "find issue" page shifts when user do mouse over

Steps to Reproduce:
1. Launch JIRA 4.0(build 137)
2. Click on "Find issues" tab and search issues for any project.
3. User gets a list of issues in that field. There is a column entry "Actions" in the last column.
4. Just move the mouse over the Actions field.

Result:
1. There is shift in UI and Actions column is outside the table. Move the mouse again and it will be back at original position.

Expected:
1. No shift of columns should be there