FF doesn't open tabs from last session

My USB stick kinda crashed recently so I decided that I would install FF portable on my C drive. However, I noticed that even I have it set yo re-open the tabs I was viewing in my last browsing session,FF opens a blank page.

I even went and installed Session Manager just to be sure, but the same things happens: my tabs do not get re-opened. The ONLY way I see it re-open the tabs is say I install a new extension and then click on the restart link that shows up in the Add-On manager.

So, any clue of what could be going wrong?