Drat! I thought I'd posted this earlier, but somehow the post got lost (probably my own fault).

32,000? This is probably an internal (software) limit of the number of files in the list for a single write. (If you investigate further it'll probably turn out to be 32,767. The maximum number that can be held in a 16-bit value, if you include -ve values).

What Pakled says makes sense. Zip up the files, then burn them.

That way there's only 1 file to burn.

Alternatively (if you don't have room on your HD for a zipped runtime), you could try burning each directory separately...or zipping each directory and burning them individually (deleting the zips as you go..)

Cheers,
Diolma