Secure vs. burst vs. iTunes ripping

The more ripping/encoding of my CD collection I do, the more intrigued I become by the process. Case in point:

While ripping U2's Joshua Tree album, Track 6, Red Hill Mining Town, would not rip accurately, with the error log showing over 400 inaccurate frames. I tried every variation I could think of with Secure and Ultra Secure modes, including trying all of the variations on each of the two drives I have on this computer - Pioneer DVR 115-D & Optiarc AD-7240S. In each case, dbpa would rip and encode the faulty track & move it to the error folder (as specified by the "Move Destination File on Error" dsp). I went through over 20 different variations and got the same inaccurate results. I also listened to each one of the ripped tracks and heard the same approx 30 sec section of skips and pops, so it really was an inaccurate rip as reported by dbpa.

I also tried ripping the track in EAC and fb2k with the same inaccurate rip results and the same skipping and popping in that 30 sec section. So I was ready to give up and to pay to download that track from one of the download sites offering higher quality downloads (high kbps MP3 and FLAC files).

Then it occurred to me that I had ripped this CD a few months ago with iTunes, before I started using dbpa. When I listened to the 336 kbps AAC track ripped on iTunes, I heard none of the errors I heard from every other ripped version of the track. I thought I might have damaged the disk since I ripped that track on iTunes, so I re-ripped it in iTunes in 196 kbps MP3. I got the same result - no audible errors. So I thought that maybe the secure mode of dbpa, EAC, and fb2k was introducing the errors, so I ripped the track in dbpa's Burst mode. Same result as with iTunes - even though dbpa reported the rip as inaccurate, when I listened to the track burst ripped in FLAC, ogg vorbis, and m4a, I heard no audible errors.

[LIST][*]Why do iTunes and dbpa's burst mode rip this track with no audible errors, while the secure and ultra (or paranoid) modes of dbpa, fb2k, and EAC rip the track with a lot of audible errors?[*]Is this what dbpa's Burst mode is intended to be used for?[*] Does the iTunes ripper function approximately the same as dbpa's Burst mode (that is, little or no error detection, even though I turned on iTunes "use error detection" feature)? [*]Why can't dbpa's secure and ultra modes fix the errors by interpolating unrecoverable frames (the setting I use) if Burst mode is able to encode them with no audible errors?[*]If the "interpolate unrecoverable frames" setting isn't meant to fix these kinds of errors, what is it meant to be used for?[/LIST]

Bumping this question. I'm wondering the same things, and others. I ripped with dbpa today in Burst mode and got about 4.7x speed. I ripped in Secure mode (not Ultra) and ripped at about 13-14x. Huh?

Perhaps co-incidence, the CD drive decides ripping speed for the whole disc just before ripping.