Searching in internet for the easiest way to fix my gps after updating to DK28...I came across with the following instructions from user WorldWide (pcgeek forum):
"Fixing the GPS no fix issue on the Samsung Epic 4g requires you to do a manufact...
check this video tutorial :D
buy a cable...I had the same issue until yesterday... I went to staples and I bought a new cable for $19.00...problem solved. :)