Did you register your serial number in your Planet Auran profile? If not then that would be the reason why you are getting that message. It could also be that you are trying to get content that was made for a higher version of TRS that you own.
1) Click on Profile (next to Register on the top of the forums)
2) Log in
3) Click on SERIAL No.
4) Put in your serial number which can be found on the back of your manual or on a sticker or on the CD case.
5) Select your Product ( Trainz Classics, TRS2006, TRS2004, UTC, Trainz)
6) Select your purchase location
7) Click Submit.
Viola you have successfully registered your Trainz product and now have access to 50,000+ assets on the DLS.
Also I notice that you have 2 profiles I would suggest that you send a message to helpdesk to see if they can merge the 2 accounts.