User gets a system error if after timeout tries to login from project avatar dialog

Steps to Reproduce:
1. Launch JIRA 4.0(using bamboo build 139 Trunk)
2. Login as project admin and edit the project.
3. Click on "Image" next to Project avatar to edit the image.
4. Now suppose user was away from computer for 30 mins. when he/she comes back and tries to upload an image, its says not login and give a link to login.
5. Click on login link and a login window appear in that small window only.
6. User enters a valid userid/pwd.

Result:
1. User gets a system error. Complete log file attached.
2. I was not sure the issue belong to which area,as got with project avatar dialog will let Chris assign it to appropriate person.

Expected:
1. No error message should come and user should proceed with the work