Album Art issues - copy purchases between computers via Home Sharing

I am copying iTunes music purchases from my MacBook Pro to another authorized computer (PC with Windows 7). I followed the instructions in these articles:
iTunes for Mac: How to copy purchases between computers <http://support.apple.com/kb/HT1373>
iTunes 9: Understanding Home Sharing <http://support.apple.com/kb/HT3819>

I have been successful in copying music via Home Sharing from the Mac (Computer 1 with original purchases) to the PC (Computer 2), but the album art is not appearing on the PC. What solutions can you offer for this issue? Thanks in advance.