Hi Tom,
I cannot produce this problem using the latest version so I would suggest upgrading.
In the meantime if it helps it is confugrable what the threashold is for changing from the dropdown, the default is if you have 150 pages or more but you can override it by putitng this in user.config and setting a higher value.
<add key="TooManyPagesForDropdownList" value="150" />
Best,
Joe