The signatures are probably cached by the site to save resources, so it didn't update right away. I've noticed other vBulletin sites doing similar things now and then; it usually clears up in a couple hours at most.
1995 Airstream Classic 30' Excella 1000
2014 Ram 2500 Crew Cab with Cummins 6.7L Diesel
Sold but not forgotten: 1991 Airstream B190
Sold: 2006 F-250 6.0L Powerstroke Supercab