several issues since upgrading to WP2.7

I am fairly new to WordPress. Since I upgraded to 2.7, I am experiencing several issues and I really need help.

I am unable to log in to Worpress except as admin. I want to log in with my user name, but cannot.

I am unable to access my plugins list on the dashboard; I simply see a text box that says I have x number of plugins installed. One or more of them needs to be deactivated, but I am unable to do so. I am getting the following error on the main page of my blog:

Warning: implode() [function.implode]: Bad arguments. in /mnt/local/home/angelsong214/angelsong214.com/adiml/wp-includes/query.php on line 1805

Also, on the dashboard, I am getting this error in the draft post section:

Warning: extract() [function.extract]: First argument should be an array in /mnt/local/home/angelsong214/angelsong214.com/adiml/wp-content/plugins/dashboard-draft-posts/dashboard-draft-posts.php on line 50

and this one on the scheduled posts section:
Warning: extract() [function.extract]: First argument should be an array in /mnt/local/home/angelsong214/angelsong214.com/adiml/wp-content/plugins/dashboard-scheduled-posts/dashboard-scheduled-posts.php on line 50

I think these errors are likely plugin related. Please help, so I can once more enjoy using WordPress.