Go into the Coppermine config and try removing all of those images at the bottom of the Coppermine Index page. (Last updated albums, Last additions, Last comments, Most viewed, Top rated and Random pictures). All those db queries would be my first guess as to what may be bogging your db server.
Also I'm no fan of how Coppermine claims GNU/GPL, but tries to force people to keep the "Powered by Coppermine Photo Gallery" link at the bottom the page. To top it off they make the code rather difficult to find, so if you want to remove that edit your theme.php and search for the line "echo $template_footer;" then simply comment it out by adding "//" infront of it.