Stuck In Maintenance Mode

Hi,

This morning I upgraded 3 plugins on my site, SEO Ultimate, Newsletter Sign up and WPe-Commerce. The 1st 2 upgraded OK but the 3rd, wp-e-Commerce hung and now the site is stuck in maintenance mode with a “Briefly unavailable for scheduled maintenance. Check back in a minute” displaying, even when I try to access the Dashboard.

I’ve tried deleting both the WP-eCommerce & Maintenance Mode plugin’s by deleting the files from the Plugin directory on the server by am still locked out. Any ideas or suggestions please ?

Holmey