Simple Tags problem: Tag tool not showing up on “Post” pages

I installed Simple Tags 1.5.7 on my WordPress 2.6.2 setup, and for some reason, the “Tags” tool on the “Post” pages is now missing, but it shows up on my “Pages” pages. I have uploaded screenshots so you can see what I’m talking about: Post Page w/o Tags Tool & Pages Page w/ Tags Tool.

In addition, the “Suggest Tags” tool on the post pages isn’t functioning properly. If I click on it to open it, it’s empty. If I then click on “Local Tags” “Yahoo Tags” or “Tag the Net”, it simply toggles the tool closed again.

To verify that the problem was with Simple Tags, I deactivated *all* of my plugins and verified that the Tags Tool does work on the basic installation, and it did. Then I reactivated ONLY Simple Tags, and the problem reoccurred.

I did have a previous WP 2.6.2 set up using Simple Tags 1.5.7 (the same versions of both that I’m using now) and Simple Tags worked just fine – but for some reason, it’s giving me trouble now.

Any suggestions would be MOST welcome!

Thanks ??