[Plugin: TinyMCEComments] Very “interesting” problem in wp 2.9

When I activate MCEComments 0.4.8 in WP 2.9 my access to the widget admin page is just gone. If I deactivate it it comes back.

This is true for a few other plugins that worked perfectly well in 2.8.6 -namely: Different Posts Per Page, Gallery Shortcode Style to Head, Google XML Sitemaps and StatPress Seolution.

It is a very strange phenomenon, and if anyone have any idea why that is I would be grateful to hear of it.

The symptom is a blank page, no error-message or anything – just blank.

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