FLAC to ALAC -- plays in iTunes but won't sync to iPod Nano

[Ordinant]

On Windows 7, 64-bit
dbPoweramp 14.1

1. Bought music in FLAC format from HDtracks.com.
2. Converted FLAC to Apple Lossless (ALAC) using dbPoweramp.

These files import into iTunes 10.6.1.7 normally and play normally.

However, these files won't...