I'm not on FF3 - there were reasons for not installing it when it came out, those reasons have gone but I've been too busy to mess around.

Strangely 2.0.0.17 (on the laptop) now works OK - it started working after I disabled and then re-enabled an add-on which is totally unrelated but which seems to have played havoc with Expedia.

Tried the same on 2.0.0.18 but it didn't cure the problem. I can log into Expedia, I can get as far as asking it to find me hotels in a specific town on a specific date... but when I try to do anything with the information (book, or even just click the "find hotel on a map" link) the whole thing just comes to a grinding halt.