It's been 15 years since I played with packet, so I don't remember the text string you send for general APRS (is it wide-wide ?) but somewhere on that website will have instructions to keep your digipeats on the right network. And perhaps all the right strings are programmed into the radio's TNC already?
My old Cali club were the first people to support the Baker to Vegas Relay Race with APRS, tracking our team over the entire 120 mile course. Way before handheld consumer GPS. It was whiz-bang stuff back then. Really impressed the law enforcement types.
I would love to get APRS running again so you're not the only one. And then Jeff would join in the fun as well. Would be cool, assuming coverage, to see specific rigs on the map during something like the Ghost Town Run. And if we created our own digipeater for the comm. trailer, we could see every trail-boss and tail-gunner at CM.