blocks module displays only the admin settings- user themes will not display

I am using a newly upgraded version of Drupal 6.4. This problem just appeared yesterday after I had setup a number of new features and menus on the site. When I access /admin/build/block/list/pixture or admin/build/block/list/garland or any specific theme within the blocks module I get only the blocks assigned to the admin them and the page display remains showing the admin theme instead of the one I wish to update. If I select a User theme specifically on the blocks page the screen updates as if to show that I have this option selected, but the list of blocks assigned and the screen graphics remain showing the admin theme. My Admin theme is currently rootcandy but it doesnt matter what themes I have activated this behavior persists. I have tried this with all themes set to drupal defaults.

The only way I have found around this is to assign the theme I wish to modify in blocks to the admin using the admin/theme function. I can then change the block settings for the admin theme and these changes are kept when I save the form and switch the admin theme back to the correct one. I'm happy to have a workaround, but I would prefer to have a site working correctly. Any hints? I have emptied all cache files and tried this on multiple browsers and comps.