Dock connector - no audio output

I have an iPhone 3G running 3.0

I know or have figured out that the 3.0 update removes the volume bar from the iPod mode when plugged into a dock. "+You don't need them+", so it slides away when connected.

I have a similar problem but thru different actions. When I use the transmitter in my car that connects thru the dock port, occasionally I lose audio function thru the iPhone's speaker when disconnecting it.
The volume bars disappear -- or never reappear-- and it behaves as tho it is still plugged into a dock. A restart of the iPhone fixes this problem temporarily (by temporarily I mean that's a pain in the a** b/c it just happens again after another car ride) The iPhone stays like this (without volume bars or sound) even when I plug into my laptop, sync, and try to use my iPhone for audio while still connected to the computer via USB.

Another annoying fix I've discovered:
If I plug in to my dock station at home (a macally alarm clock) it plays thru because it was playing music thru as tho it was in a dock all along. (unless I hit pause and quit the iPod function of course) When I remove the iPhone 3G it finally realizes it's not in a dock and functions normally.
I never EVER had this problem before 3.0. I assume it's software related b/c a restart fixes it. I also think it might be related to the phone being on vibrate when I put it in the car dock transmitter... but that's yet to be determined scientifically.

*I think the software is reading docks incorrectly in function and presence.* That's all I got.

Thanks!

If you’re using the optional dock’s line out port, the volume is controlled on the device you are connected to.