Yeah i have the same issue, ive tried some of the things around on the web (like deleting update) but ive had no luck, i cant install any plugins or updates now. +1 looking for help.
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Try delete the upgrade folder in wp-content, make a new directory as ‘upgrades’ and change to 777 via ftp as a possible fix for the plugin issue that might come from the 3.0.3 update fail i came across.
-edit-
nevermind, your post either changed or im really tired and hardly read it, sorry.