Unable to add sub-pages to Wiki

Dialog box functions normally but no page is actually created after entering details and hitting create button. No error message is generated. Tested on both of my wikis and attempted to add sub-pages to various existing pages. Able to create a new page, but also cannot add a sub-page to the new page.

Attempted to add sub-page both via the Page Options pull down menu and the Add Sub Page button in the Navigate Pages area.

As a work around I am able to move a newly created page to the needed position as a sub-page via the wiki site map.

System: Mac OS X Lion (10.7.2), Safari (5.1.1), Firefox (8.0.1). All up to date as of 24 November 2011.

Thanks