Both my wife and I have Fascinates and both of us have experienced issues with our applications randomly rearranging themselves. I spent quite a bit of time getting the Applications pages setup the way I wanted it, with all the pre-installed crap I don't want/use pushed to the last couple pages and everything else where I wanted it. I've since given up trying to keep my Apps organized because they've changed so many times. (estimated somewhere between 5-10 times in the last 2 months they've randomly changed position). When it happens, it seems to follow some other fault, i.e. either a force close of a hung application or a hard reset because Android froze. However, it does not happen after every fault/reset. It is just annoying to have to hunt for the app you want to run because it is not where you last left it.
Also, I've liked the phone so far (I've only had it a couple months) but just about every issue I've read on the first three pages of this forum both my wife and I have; Phone not ringing/no missed call when people call, phone randomly takes screenshot when trying to sleep the phone, & GPS taking FOREVER to lock. Incidentally, I keep my GPS off until it is needed (usually when Google Maps/Navigation takes me to the settings page because it want's it enabled). I say that because I believe someone was asking in another thread.
Sorry about the rant, since I was having so many of the same issues as the rest, I was curious if the roaming Apps issue was also common.
Thats a strange one, maybe you should try ADW EX because it has a option to lock the launcher so norhing can be moved, deleted or added without unlocking the desktop.. Plus in my opinion it runs smoother than the stock interface in every way...
I found it much easier to have my apps on the last page and let the pre-loaded apps stay where they are on the first couple of pages. While I'd prefer to have my apps first, at least they are all together. I found it far too much work to try to move them around another way, plus it shifts some things around in a way that I did not intend.
BTW, I definitely prefer the Fascinate's arrangement of the icons over the Droid X2, which is always in alphabetical order in a vertical non-stop continuum.