What exactly are your "my mpeg2 TV recordings", are they real mpeg2 files or are the *.TS or *.TP stream files? If they are the latter type streams, then you need to extract the mpeg2 file out of them first, I use HDTVtoMPEG2 for that.
Also dont get put off by TMPGenc DVD Authors bitrate is to high error. When CCE has the flag "DVD Compliant" turned on it stes the streams header bitrate to 9800 regardless of what the actual bitrate was useed in the fle. TMPGEnc is just about the only authoring program that simply reads the header bitrate rather than determine it itself. Load the same file into any other authoring program (Maestro, Senarist, DVDLab, DVDAuthor, etc) and it will NOT give you that error.