Well then, it's probably a space problem. Let me explain:
Songs are stored into your PC's memory in a compressed format (mst likely), like .mp3 and .wma. To make a CD that will be read by any CD player, you must first decompress it, which results in a much larger file than the one that you have in your comp. You see where I'm getting at? Say you have a 43MB .mp3 file that you want to put on CD. Now, unless it's an .mp3 CD (in which case the 43MB file size applies since the file remains unchanged) then the file while be decompressed into a very large file (probably .wav or .aif). This will in turn cause the CD to fill much quicker than you thought.
Want further proof? Take a CD and look at it's, uh, 'underbelly' .Try to write a CD (music CD, not .mp3) out of that album file you got. Half of the album will get on that CD. Take the CD out of your comp and look at it's readable surface (readable by the laser lens, not you). You should be able to see a darker surface which represents the amount of data that has been burned on the CD. If that surface is big enough for it's limit to be real close to the CD's edge, then that means that the CD is full and all I said earlier is true. If it's not, then ignore whatever else I wrote up till now and wait for another reply.

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iMac G4 OSX 10.3.9
RAM 256MB
LW 4.10.5 Basic
ADSL anything from 3 to 8Mbps/around 1024kbps

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