Thanks, I just went ahead and tried it after reading further and seeing mentions of 3.4 in the text files, and it of course works just fine.
Sorry, first attempt at jailbreaking anything, didn't want to muck it up!
Installed the screensaver hack so I can get the current book cover as my screensaver (wish I could do this for my PW2, but it auto-updated on me a while back). Not sure what else I want to do, might try the fonts next...
In saying that, at the moment this K3 is unregistered (I originally planned to give it away to a relative but instead I've loaned it out to a couple of people with a handful of DRM free books on it for them to try out). I could just re-register it to my own account but quite like the idea of having it as an "off radar" Kindle. Is there anything I need to do to it to help with that? Is there a simple way around registering to get collections to work? The thread I found in here looked like it involved a fair bit of work, and, well I think I'll take the easy option and just register it in that case!