upPrev in options.php

Hi,

I noticed that upPrev create a lot of options in the hidden admin page options.php.
They are so much that the page is extremely slow and I can’t read it.
For example the are a lot of options like this: _site_transient_iworks_upprev_box_ then an ID and a date. In the corresponding field there’s the HTML of the upPrev box.

I deactivated the plugin, but the options are still there.
Do anybody knows how to delete them?

Thanks and sorry for my bad english.
Giovanni

http://wordpress.org/extend/plugins/upprev/