CMS CMS Articles issues, need to clear the cache to make them published
 

I have an annoying issue, I guess since I installed vbSEO 3.6 PL2 over vBulletin 4.2.0 PL2 (now it's upgraded to 4.2.0 PL3); everytime a user (with the right permission, actually supermoderators) write an article but he/she decide to publish it later, it simply remains "not published", the "Published" option into the article edit page always remain set to "No" even if I select "Yes" and click "Apply" or "Save", so everytime I have to clear the cache to make it published, the issues are almost the same as some user report in this thread.
I disabled the vbSEO plugin by the vBulletin admincp (Plugins & Products -> Manage products) and write some test articles, it works, but it's not a solution for me, I need to keep vbSEO enabled.
I need your help, thanks.