708A is a piece of shit. do a search on this forum and you will find out.
Every brand of dvd burners have problems with media. Check the other forums like Pioneer, LiteOn, & Nec.
I have a 708A and have had no problems with the drive. If you read the postings in here alot of the problems are with people using cheap dvd media. Plextor has a "RECOMMENDED" brand of DVD MEDIA they support as well as a "COMPATIBILITY" one. If you use cheap media you end up with coasters. Some of the compatibility brands will not work on the 708A.
Plextor having a very very very....VERY high reputation, i was expecting a drive that could read everything. I guess along the years, their quality has fallen badly.
Plextor has a reputation of quality made drives that use quality cd media as well. I agree the CMC cdr from Memorex are not the best but I use them and they work fine and can be read by my 708A.