vehicle return for no apparent reason

The situation:
Flying through the clouds of Zoe I get these messages:
[7:07] Second Life: Can't move object 'vehicle wing' to
{ 2.49514, 207.054, 2641.82 } in region Morris because the parcel does not allow objects to enter from other parcels. Notifications from this region are temporarily deactivated.
[7:08] Second Life: Your object 'vehicle wing' has been returned to your inventory lost and found folder from parcel 'Welcome Area' at Morris 8.93395, 203.814 because it went off-world.
The vehicle is not returned in this case but in multiple cases, it has been returned and often I wind up in dead and buried under ground.
Note: Morris is approximately 5 sims away.

It's great that Linden Lab added security for landowners, but the security is so severely buggy that it makes one of the oldest and coolest functions of Secondlife virtually unusable. I see newbies in vehicles every day, proving that people WANT them. Is "failure to deliver" the first impression that Secondlife wants to give?

In my opinion, this is the next thing the bug hunters should be looking at.
Right now, I have far greater respect and hopes for our elite squad of bug hunters than the feature writers (who seem to have their heads up their egos). This problem is CORE to SL operation. The inability to support 1.1 features should be an embarrasment to every "feature" coder thereafter. Upgrades shouldn't be a tradeoff/ Vehicles don't have to suck.

Yep, I've bug reported this over and over again. There's actually two bugs here:

1. Most of those messages you get are actually false positives. Nothing happened, some code in the server is printing a message, then going "oh, that's a vehicle", and letting you go through.

2. Some of the time, usually with a full parcel, it's not checking whether the vehicle is a vehicle (vehicles are supposed to be counted against sim overhead, not the current parcel) and *starting* the return process, then abandoning it partway through.

The latter bug is what's causing you to be half-unseated while flying, while the plane flies on. I don't know precisely which order it's doing things in... either the sim has told the client that you're unseated but it's still associating you with the vehicle, or the sim has unseated you but hasn't notified the client or the vehicle. Either way the updates between the client and the vehicle and the sim are broken.

The client is still talking to the sim you were in and that sim has handed you off to the next sim, or vice versa. So you can't unsit because the sim it's talking to doesn't know you're there. You can't move because the client is sending control events to a vehicle that's not getting them. You fall forever because the client isn't getting updates from your sim.

The fix to both bugs is for the sim software to check for a vehicle earlier in the process, and not go down any of the code paths that lead to you getting these messages or unseating you.

There's a related problem that happens when you hit an actual ban line in a vehicle. They've added some code to automatically unseat you if your vehicle is found inside a parcel you don't have access to (this is unnecessary, since you can't use this as an exploit to let you into the parcel) and again it's following the "bad" code path that leads to the partial unsit.

Had a half thought about why prims jump around when editing them being partly related, in that the client's data of prim location should be considered correct (while it's being edited), I think my thought was that the updates not working correctly is screwing that up as well.

That's a known problem with lost packets. It's related in that the client is out of sync with the server, but this isn't due to packet loss... it's 100% repeatable at any time, once you've found a place where it happens... it's a problem in the sim's logic.