There are probably errors in the kuid files. The only error correction tool available to TRS2004 users is TO (TrainzObjectz) available from http://www.tafweb-trainz.co.uk/downloads.html
To add to rweber suggestion, you must also install "Paint Shed". for some content to show.
Could you let us know what OS you are using incase there are other helpful hints we could give you.