I also noticed it being difficult to seat tightly enough to get the phone to make a connection with the micro USB. It seems to have gotten easier with a few days use, but I still have to press firmly.
I have a more pressing concern at the moment though. I used te seidio dock with the standard battery and while it was definetely getting a connection to the dock (charge indicator showed on the power display, showed conneted to AC, backlight stayed on), it was not actually recharging the phone. At least not much. I would leave a client and have an hour drive. I would leave with 70% and arrive at my destination with 40%. I would run GPS or music, but USB transerfers more then enough power to supply your usage and recharge the battery at the same time. I haven't tried it with the entended battery (which is the whole reason I got the dock) since I had to have my first one replaced and my new extended is still going through the full charge/discharge sequence they recommend.
So, has anyone else noticed it making a connection and not charging the phone sufficently?