When starting my car, I have the same battery issue most times. Also remember that when starting most cars, the accessories line will be disconnected (among other things) to ensure as much power is available as possible. I don't think a 1 or 2 second pulse on the switched line causes the battery icon to appear though it might make it blank the screen. At least that's what I see. It can be kinda annoying because it blanks the screen just as my animation is going.

I'm in Australia and had the same plugpack problem. If you're in NZ try Jaycar for a MP3137. A$32.95 for a 12V 1A switchmode which works flawlessly with my empeg with 1 30G drive. I originally tried a crappy Dick Smith 12V 1A unregulated thing and it wouldn't cut the mustard. The Jaycar is also quite light and compact (being switchmode) compared to the DS one. And would beat carrying a bench supply around too if you want to use your empeg at a friends house or something like that