I tried iActivator yesterday and the process worked very well, but....

After I get "out of jail", if I open iTunes it shows my iPhone to have only 300Mb of Flash and most of it full (I didn't realize it in the first place, but at some point iTunes complained about not being able to sync more stuff because the iPhone was full).

If I go "back in jail" my iPhone shows again 7+ GB free

I tried multiple times always with the same result. Everything else seems to work just fine.

Very strange!

I had the same thing, you can return to jail everytime or replace the Services.plist on your iPhone with the iPhoneinterface tool. Search this forum.