|The cda files are quite normal. Think of them as shortcuts to the actual material on the CD. They should play quite normally on your home stereo too.|
I don't know the reason why they only play on your computer but here are a few possibilities:
Make sure you are burning them as an audio CD (including Finalizing or Closed Session - whatever your burner calls it). On the face of it you appear to be doing so.
Sometimes home stereo drives can be very fussy about the brand name of the CD you use - so try another brand.
Try burning at the slowest speed possible - I've found this often helps.
Maybe there will be some more ideas from others.
How to know you are getting old 3:
You start converting your age to hexadecimal