Not sure if that drive allows such overburning (should check but pushed for time right now), but you say you enabled overburn?, sorry if this is a silly question, but did you also set the maximum CD length appropriately? I still use Nero 5.5.xx.xx - works for me until I get a newer cd/dvd recorder combo
Even if the above is satisfied, sometimes an image or set of files is just a fraction too large to fit on the media with overburn enabled. In my experience, best quality media often has slightly less space than some cheaper media - the time stamped onto the media meets official specs, but is thus slightly worse for excessive overburning.
Once thing with Nero 5.5.xx.xx (possibly 6.x) - is that ISO's that are large (cd or dvd) are often rejected by nero with the complaint 'not enough space on media'. For example, with an ISO image of 4.7ish GB's (DVD in this case), nero will not burn the image - if the files within the image are extracted using ISObuster or Daemon tools, the actual total size of files is smaller than the image would suggest - and they all burn with no problem at all.
This may all be irrelevant for your problem - just food for thought.