Wow I wish it was just as easy as it used to be with my old Plextor drive. Plop a CD in and wham you have a disc burnt 
Anyway I had some problems previously with errors on discs occuring without fail - I’ve solved it somewhat by burning at a slow speed. Why is this and is it a problem for hardware or media or software or what?
Should I be concerned? (need to know if returning the drive is neccessary).
we need more information??? what are you talking about??
What burner,what firmware,what burning program,what media,ect???
http://club.cdfreaks.com/showthread.php?t=131801
Pioneer 109 using 1.40 Firmware
Media is Verbatim (48xCD-R), Eperfomance (4xDVD+R) and some unbranded CD-Rs.
Software, Nero Burning Rom 5.5/6 & RecordnowMax 4.5 (I think)
Im not sure what Eperfomance is? I would not use it(even if it was good media)because its only 4x. The faster burners(such as your pioneer109) Don’t like trying to burn at such slow speeds with the 4x media. Try getting a good brand name dvd media at least 8x speed and try it. Are you sure you have DMA enabled and not Pio, are you sure you have a IDE 80 pin cable and not a 40? Your ASPI OK? It could many things.
What does ASPI mean?
I’m sure I have IDE 80 ‘wire’ cable, but I do have another DVD rom drive ‘slot in’ drive connected as slave if that means anything - it’s another Pioneer drive too.