Only One KB Advanced RSS Widget Available

Hi there,

I had an issue with the KB Advanced RSS Widget whereby trim settings were ignored, causing me to remove the feeds from my site. This has been resolved by upgrading to WP 2.8, but now a new issue has appeared whereby only one widget becomes available in the Available Widgets area, despite selecting multiple in the drop-down at the foot of the page.

Perhaps related, once hitting the save button at the aforementioned drop-down, refreshing or leaving the page (in Firefox) displays the warning:

To display this page, the application must send information that will repeat any action (such as a search or order confirmation) that was performed earlier.

Any help on this would be much appreciated.