Global site search causing error on post publish/update

Hi have just installed Global site search on WPMU 2.8.4a.
It works as far as the search page is concerned, but I get error on publishing or updating posts:
on Firefox, the page does not return to the posts list after the update.
on IE, I get the DB error copied here:
"
WordPress database error Incorrect datetime value: '1253823287' for column 'term_count_updated' at row 5 for query UPDATE wp_term_counts SET term_count = term_count + 1,term_count_updated = '1253823287' WHERE ( (term_id = '1' AND term_count_type = 'blog_type_Blogs Perso') OR (term_id = '1' AND term_count_type = 'blog_lang_en_en') OR (term_id = '1' AND term_count_type = 'all') ) made by edit_post, wp_update_post, wp_insert_post, do_action, call_user_func_array, post_indexer_post_insert_update, post_indexer_post_terms_insert_update
"
I have tried to remove the datetime format in the field term_count_updated, but I still get the same error.