(xoben @ May 22 2009,01:58)
1) Your DVD+R DL disc is damaged. Try other programs such as CloneCD will get the same performance.
2) Your disc is copy-protected. It is recommanded to install AnyDVD from SlySoft, then try again.
Ok, so I tried CloneCD and didn't get very far with it either. I decided to try my other optical drive (PLEXTOR DVDR PX-716A 1.10) and that worked perfectly -- completed in 22m11s. According to Vista's Resource Manager, UltraISO's peak write rate was around 620MB/min!
So, must be some incompatibility between the TSSTcorp drive and the Verbatim 2.4x DVD+R DL media.