Is Firefox incompatible with the extension, or the extension incompatible with Firefox?
Chicken or egg?
Given that the extension was on this planet before Firefox 3.6 existed, you'd have to say that v3.6 is the incompatible bit.
I
could try one of those forced compatibility things, but there would be little point? I only use Firefox for perhaps 5% or 10% of my browsing, so it really doesn't matter a lot. In fact, come to think of it, I can't think of a single useful feature that's in Firefox 3.5 or 3.6 that isn't already in (say) v2.0 - possibly even v1.0, though that's going a long way back and stretching the memory. Not saying there aren't any, just that I can't think of any off the top of my head. So the only major reason to switch is security, and that only becomes a factor when they stop doing bug-fix releases on the 3.5 branch. I'll just wait.
Opera: {Tools} {Delete Private Data} click [Delete] ... done.
Yup. But that deletes
all the data! I frequently just want to delete the stuff for one particular site that I'm testing code on. The easiest and quickest way to do it is copy the address, close the browser, reopen the browser, paste the page address - <control-insert> <alt-f4> click <shift-insert> <enter> Takes what? Three seconds including a scratch?
Edit: Oh - but that assumes, of course, that I'm not using the browser in question for anything else at the time. This is where Firefox (and lately also Chrome) come in handy: I mildly dislike using them, so I generally don't have much open that will be missed, where closing Opera or Seamonkey often involves a lot of mucking about saving stuff I'm working on.