Microsoft is deprecating their image search on august 1st so the latest update of gmmp is now using a replacement service. The results seem to be more accurate.
1.3.7 (07/31/12):
-Replaced album art download service (old one stops working as of August 1st)
-Improved album art searches for poorly tagged albums
-Improved image loading speed when scrolling the album list
-Increased the timeout for loading large audio files
-Added option to use older mp3/aac decoders instead of opensl (uncheck Prefs -> Audio -> Enable OpenSL)
-Fixed crash related to cue files
-Fixed restore crash on HTC Sensation 4G (4.0.3)
1.3.7 (07/31/12):
-Replaced album art download service (old one stops working as of August 1st)
-Improved album art searches for poorly tagged albums
-Improved image loading speed when scrolling the album list
-Increased the timeout for loading large audio files
-Added option to use older mp3/aac decoders instead of opensl (uncheck Prefs -> Audio -> Enable OpenSL)
-Fixed crash related to cue files
-Fixed restore crash on HTC Sensation 4G (4.0.3)