Sorry to hear about the crashes and thank you for the report IDs.

Three of the reports are "OOM Large" and two are "OOM Small" indicating that Firefox wasn't able to obtain needed memory from Windows. Since all of the reports indicate a lot of memory available, it's not obvious why that happened.

One possibility is that you somehow hit the maximum allowed for 32-bit programs. I guess "somehow" isn't fair because I find after a while on Facebook that Firefox is nearly dying as a result of having to manage all of the tab's endless content. You may be using sites with similar high memory demand. One option to consider is switching to the 64-bit version of Firefox, which can use more memory. This article has more information: How to switch from 32-bit to 64-bit Firefox. I'm not sure the Adobe extension is compatible; if you use it a lot, that might be a reason not to switch.

The sixth report doesn't look familiar but the memory situation looks similar and when I look at the comments other have posted about this crash with their crash reports, there are numerous references to Facebook. So I suspect it may be a different description of the same problem.

I see that you have an older lastpass.com:3.3.4 version. Maybe you should update the the latest version (4.1.44): http://lastpass.com/