Still no idea why some Kindles (FW 3.x only) fail to load some fonts... The only time that ever happened to me, that was with the *default* fonts (ie. Caecilia), and it worked fine 5 minutes later. >_<".
But, using a freetype override (bci or autohint) seems to 'fix' it, so my guess would be a weird freetype bug/interaction bug with the Java framework in the specific freetype version (or paches?) bundled with FW 3.x. That doesn't really explain why it only happens on some Kindles, though.... -_-"
EDIT: Yep, a straight Kindle to Kindle copy of a DRM'd book would explain the PID mismatch

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