Looks like old Sammy has issued an update for the Samsung Vibrant which is available to download to your Sammy device via Samsung Kies. However apparently T-Mobile is saying do not download and install the update to your Samsung Vibrant.
According to an article over on Android Central by Jerry Hildenbrand, T-Mobile tweeted that the Samsung Vibrant update available on Kies has issues and warns users NOT to do the manual update via Samsung Kies but sit back and wait of an official over the air update.
T-Mobile or Samsung hasn’t offered any insight into what issues the Vibrant Kies update actually has, but it is advisable to heed T-Mobile USA’s warning, so if you haven’t already updated your device then give it a wide birth.
However if you have already done the update it is hoped that T-Mobile will be able to get the issues fixed; as soon as we hear more or what the issues are we’ll let you know.