Sorry if this has been covered before but a couple of times I've seen this really weird behaviour on vatsim. Last night e g I took a flight from EDDF to EGLL and before me another plane had taxied to rwy 18. However, when I was about to taxi the very same plane (I could read the ID of the plane)appeared close to the gate again. It taxied from my left to my right, crossing my intended taxy path and then it was back again on my left side and crossing again, on and on. Each time it started taxiing it was a bit closer to me. I asked the controller and he said that at the moment that very plane was at the rwy cleared for take off.Well, for me that ghost plane was very real because finally it slammed right into my left side and I had an aircraft collission.I restarted and the plane was there again and I had another collission :( Together with the controller we decided I could taxi in a bit odd fasion just to avoid the plane, and I took off safely.Anyway, this has happened to me one time before at ESSA and the result was equally disastrous. I guess there's nothing I can do about it, but I just thought I'd report it!Regards,Krister

Not sure about the ghost plane part, but one thing I do while flying online is turn off aircraft collisions. I've had a time before where I would just be holding to let another plane pass by, but it detected it as a collission even though we never hit each other!Jason