If you see those four stations listed on a service screen under Developer Info>Traffic Receiver Providers, this means your traffic receiver is picking up signals from those stations. Furthermore, next to the provider name you can read the actual frequency on which your receiver is picking up the signal, e.g, 088400 means 88.4 FM. So, as far as I'm concerned, don't worry, you're in business.
Just in case, make sure automatic search for stations in on.
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