A bad quality of thumbnails! Why!?!?!?
http://mustangclub.ru/gallery/thumbnails.php?album=17
If you have GD2 use that instead GD1
As Stramm suggests, this is caused when your server has GD2 installed, but your coppermine config setting is for GD1.
Change the setting in config. You should then use the Admin Tools, to update thumbs.
oh..Thanks a lot dudes!!!!!