Keyword adding error (probably AJAX problem)

I'm sorry if this is a duplicate entry I couldn't do a proper search.

Well, I have installed the cvs version of Drupal. Looks great BTW. I was playing with it and created a category to add keywords. Free tagging was selected. So, I created a story added a keyword but it didn't add to the list. Then I added the keyword in the category section. Tried again to add the keyword while writing the story, the keyword appeared and I selected it but it didn't add the story to the keyword. Several times the keyword bar which appears while you are typing didn't disappear even though I have clicked else where on the page.

I'm using Mac, this problem occured on Safari and Camino. With Firefox I was able to select the keyword but still couldn't add it to the list.