Really does make a noticeable difference in Firefox 5 but stopped working in Firefox 7 Rated 1 out of 5 stars

Stops Firefox 5.0.1 'going to sleep' when I leave the computer for a few hours.
For some time now when returning to the computer I have to wait several minutes for Firefox to 'wake up' and sometimes Windows will also display the message 'unresponsive'.
Since installing RAMBack I no longer have this problem and even in normal use I can see that Firefox is more responsive.
I have been constantly watching the memory usage of Firefox with StatusbarEx and in normal usage with say 6 tabs open it will show memory constantly being cleaned and dropping to 10mb before stabilising at around 30mb. If I leave the computer it will stabilise at around 18mb.
This means I am not constantly having to worry about my workload hiking the RAM up to near 70% or 80%.
While typing this review the maximum memory Firefox is using is 35mb out of an available 488mb.
Only takes a mere 12kb on disc as well.
I think that it does a great job.

Edit: October 17, 2011
With Firefox 7.0.1 RamBack no longer works at all.
I suppose it has done well to last up to Firefox version 5 without modification since 2007.
It is a great pity that it no longer works and that the developer has not updated it for 4 years.
It could of course be an add-on conflict but I doubt it as I have not added anything since FF5.
I have had to change the star rating from 5 stars to 1 star as a result.

FreeRAM XP Pro for Windows XP is the better choice (but note this is not an add-on)
I have now installed FreeRAM XP Pro which works brilliantly if set to 'Try to Free 100mb' and the CPU: Aggressively. There are extensive settings for full customisation to the individual system requirements. It works independently of Firefox so there are no compatibility issues to worry about. Set it and leave!

Hopefully one day the developer will update RAMBack.