Description of problem:
"Invalid Date" pops up when hovering over CV "Last task" link on Firefox

Version-Release number of selected component (if applicable):

Satellite 6.11

How reproducible:

Always

Steps to Reproduce:
1. Publish CV
2. Mouse-over a "Last task" link in Firefox

Actual results:

"Invalid Date" pops up

Expected results:

Something other than "Invalid Date"

Additional info:

Supposedly this doesn't occur on Chrome.