Oh..and 10 GPS devices in 1 month...definitely a nightmare. trust me. The TN555 is the best of the bunch so far...
I see you are correct that the traffic receiver is in the cradle. Thanks for reminding me about the alternate car kit. If it was $20 cheaper - and someday it might be - I would consider getting it as a backup if for no other reason. I would be interested in knowing if it does still show traffic reports if you are not on a calculated route. It is supposed to. The fact that the slide in traffic window seems to only indicate traffic problems "on your route" bothers me a little in that it perhaps is the only time you will see info - on a route.
You may have already looked at this - If you have a route set up and go to Settings > Traffic and then scroll down to Signal Status you can at least see if your gps is automatically scanning different FM frequencies while trying to find a station that has TMC/RDS data imbedded in a subcarrier. I have no idea what it would look like if one was in a decent coverage area and had a good signal since I have never seen traffic show up either.
Glad to hear you now have Traffic. So, it would appear your 555 did not have a traffic subscription as purchased? Now it makes me wonder if the the traffic receiver is not built in to the 555 gps cradle? Did you have to go through any setup procedure with the accessory kit to invoke traffic or just plug-n-play? Any chance you have tried the original cradle to see if you still get traffic? Not that important to know, just curious. In my mind just trying to narrow down the actual location of the traffic receiver with different models.