Anyone has an idea what this can be?
That would be because Rate Your Music added a check for user-agent, and returning 403 Forbidden if they don't like the user-agent requesting the image.
So here's an updated script that sets the user agent to Mozilla/5.0 for requesting the images.
RateYourMusic.boo
Hmm,
I got this error code when loading the scripit
Searching for scripts...
Found 26 files: [albumartexchange.boo, amazon-ca.boo, amazon-co-uk.boo, amazon-com.boo, amazon-common.boo, amazon-de.boo, amazon-fr.boo, amazon-jp.boo, amazon.boo, amazon_de.boo, artists.trivialbeing.boo, cduniverse.boo, cover-paradies.boo, coveralia.boo, coverisland.boo, discogs.boo, freecovers.boo, google.boo, itunes.boo, juno-records.boo, lastfm-artist.boo, psyshop.boo, rateyourmusic.boo, revhq.boo, util.boo, yes24.boo]...
Loading references: [ICSharpCode.SharpZipLib.dll, System.Web]...
Compiling scripts...
rateyourmusic.boo(39,13): error BCE0005: Unknown identifier: 'logFile'.