I also have had problems seemingly due to 5.5.10.20
I was using v5.5.10.15 for quite a while and have burnt many cds without any errors…
Last nite I upgraded to 5.5.10.20 and I started getting read errors on the CD’s I had burnt. I had also been burning CD’s with CloneCD, of which those read OK.
I started checking the cds using CD Diagnostic complete scan and while the cds burnt with clonecd and nero 5.5.10.15 read with 0 errors, the CDs burnt on 5.5.10.20 were coming back with errors usually at the end of the disc, and some also at the beginning.
All the CDs are the same brand from the same spindle and there is no reason why some would have a problem.
I reverted to 5.5.10.15 and reburnt my cds again and scanned with Diagnostic, now 0 errors.