Bringing back an old dead topic to live!!!
I've changes all my albumb arts to .albumart.jpg . so the gallaery did not show them back in Gingerbread.
but after upgrading to ICS all these hidden files are viewable again in the library. even .nomedia does not work.
p.s. I've used Windows mediaplayer to collect album arts and they are all small ,hidden, machine named JPGs.