I have not tried to play any "burned" cd's in our EX but I can offer a couple of suggestions. First, is it a CD-R or a CD-RW? A CD-R reflects about 60% as much light as a commercial CD and a CD-RW reflects about 40% as much. Some older players have problems with the low reflectance of CD-RW's and will not play them, I would be surprised if this were the case with a current player but it's possible. The other questions is how was the CD created? Depending on the method you used to create the copy, the disc may not be "closed" or may not strictly adhere to the "red book" standard. I would suggest trying your disks in some other players to see if the LX is the only one to have a problem.
Thanks for the suggestions, I got it working, apparently I didn't "close" the cd after copying it using Nero software. Interesting that the Sony home deck didn't mind but the Honda's did. I had to complete all the burn steps before it would work in the car.