1. I noticed that the BLP to PNG conversion script fails on BLP images that have their compression mode flag set to 3, which is true for two or three files in the extracted art files you can obtain from the WoW client.

    Compression mode being set to 3 means it's using RAW3 as the mode, which has more details outlined (including how to actually read it) on this wiki page.

    The file I tested with the conversion can be found at "Interface\Buttons\UI-PAIDCHARACTERCUSTOMIZATION-BUTTON.BLP", and I also believe "Interface\HELPFRAME\CS_HelpTextures.blp" uses the same compression mode, but I can't confirm on that one.

    Assuming that the script you're using is the same as this one then the fix is pretty small (5-10 lines max), which I've uploaded to this pastie. You can diff it manually, I think that's all the changes I did :)

    Thanks, I just tested against the first image you posted and it works properly now. Thanks much!

    No problem, noticed the issue when I was batch converting all the files - fixed it by pure luck though considering I could barely understand what the article said :p

    Just as another thing, the Artwork Browser is missing the two files I mentioned in the previous post, presumably because they never converted properly in the first place.

    Correct. I don't know if I'm bothered to do anything until 4.2.