I'm on Verizon, and every day I travel 140 miles south from NYC to Delaware. Seems every time I get past a certain point (for locals, around exit 5 on NJ Turnpike) my BIS connection drops until I do a reset. I've done the *228 and updated roaming and re-registered, to no avail. It keeps dropping every day.
Are you actually loosing the service or are you just seeing the BIS indicator dots disappear? I notice that when I go to Edge, I loose the indicator, but the BBM still works. This is on a Rogers phone and I noticed it also happened when in Maine with it last week.