Frankly, since you just don't understand, I don't know why I'm bothering to reply. The fact that WMP came up with a wav file that the dBpa converter converted to FLAC without error does not at all mean that the wav file was an accurate copy of what was on the CD. The CD could have ripped bit accurate, good, but it just as well could have skipped, clicked, popped, whatever because the CD drive couldn't properly read the disc. WMP will create an "error free" wav file of the skipping, clicking, popping, whatever was fed to it by the CD drive. There is nothing in WMP to verify that the drive wasn't feeding it garbage.

The advantage of the dBpa ripper once it is set up is that dBpa has a database of calculated checksums for most popular CD tracks and, if it has a checksum in the database it compares it to one which it calculates for each track of the CD as you rip it. If the checksums match you have something like a 99.9999 chance that your ripped file is a bit perfect match of the original. If it flags the rip as bad, then yo should listen to it. Many times it is only a couple of bad samples, you'll probably never hear the error. But other times, you'll hear dropouts, skips, clicks or pops. Then you probably want to take remedial action, dBpa just saved you from saving a bad rip. You might try cleaning the CD, you might try ripping it in a different drive. (I've had plenty of CDs that won't play well in one drive, but play fine in a different drive) If you have dBpa set up for secure rips, and the track isn't in the checksum database, it will try ripping the track several (depends on how you set it up as to how many) times. If all the rips calculate the same checksum, you are pretty likely to have a good rip, most times if you rip a bad CD, the errors aren't exactly read the same, and the checksums won't match each other.

Look, you can do whatever you want, but the people who have been trying to help you are all very experienced in audio and in using dBpa and similar software. Except for Spoon, who wrote most of the software, we don't work for Illustrate/dBpa, we're just users trying to help others out. Many of us, myself included ripped CDs using programs like WMA, Itunes or Winamp, only to discover that some percentage of them were bad rips, as described above. And many of us found it necessary to rip our collections all over again, using a ripper that had external means of verifying that we had good rips.