You did it that way and the album art shows up on the player?
I have the Z5 also. I tried the albumart.jpg (both small and large). Didn't work on my player. I just tried it again after reading your post. No luck.
I had to tag them w/ WMP10 (find album art)and then sync them over. Works fine then.
You can also use the advanced tag editor in wmp10 and put any picture you want as album art.
Right, so normally you should right click on a track or list of tracks in WMP10 and click 'find album info' in order to get your album art, then transfer the tracks over to your player as normal. What if some of those still have problems not showing album art (like two of my albums I didn't use the default album art for) or WMP10 couldn't find album art for some tracks?
Okay people- listen up!! Album art isn't a problem now, for anyone! I have found out that you can put any picture in an album folder on the player and it will become the album art for that album! All you have to do is follow these strict rules: 1) Don't go overboard with the size- 100x100 pixels is fine 2) The file MUST be labelled 'albumartsmall.jpg'. So, you don't even need WMP10 to find album art if you don't want to. But it does mean you have to make sure that jpg file is in the folder with the music to get the album art. What you can do is still use WMP10 to sync with the player, and if there are any known albums that don't normally display album art or haven't got it, move the jpg file over afterwards. Or if you drag and drop your music, just make sure the jpg file goes over to the player along with the music. Simple. No-one has to be without album art now. (very handy if WMP10 can't find album art, like on a few of my albums and single tracks).
PS. The easiest way to find your album art is google image search- save the file directly into your computer album folder