Now in late version 37, the problem still persisted for me.
(WARNING: Always backup your firefox profile before testing other version!)
I tested using their version 38-beta8 candidate. Problem still was around. I tested their alpha version of 40, but still it persisted.
More googling revealed a new solution I hadn't tried: Refresh Firefox
Refreshing cleans out all prior add-on settings and caches.
Here is how to do it.
- Click the menu button and then click help .
- From the Help menu choose Troubleshooting Information.
- Click the Refresh Firefox… button in the upper-right corner of the Troubleshooting Information page.
- To continue, click Refresh Firefox in the confirmation window that opens.
The good news is this worked. My memory usage is down a lot, and pages are loading much much faster.