Anyone who has used eclipse for a long period of time will have been exposed to the dreaded workspace crash. This is where eclipse decides to close itself and in the process corrupts your entire perspective layout. This in turn resets all of the perspectives you had open prior to the crash. I tend to have additional views open like Subclipse, Mylyn, various consoles and task panels so it’s kind of annoying when it happens from my point of view as I have to go and set in all back up again. You can save your custom perspective (there is an entry in the Window menu where you can save it) so all is not lost.
Now ordinarily that would be perfect, but if you apply this to a Flex perspective you run in to issues. For some reason if you save a custom Flex Development perspective the Design view loses all of the Design view specific panels – Component, States, Properties etc. You can add them back in manually but they no longer show and hide when you switch between the Code view and the Design view.
Obviously this looks like a bug, but beyond this defect you can still work as you would normally. Hopefully this issue will be resolved in the next version of Flex Builder, until then it’s broken but usable.