I have heard that CR only displays the first 500 or 1000 of a list. There are various hacks around, but I don't know them nor if they work for the OS that you are using.
My company doesn't use the parameter page, we have created our wizards that don't have these limitations, which is why I don't know the work around.
You might try thinking of some other solution, as having you user scroll through hundreds of listings would be a pain. Perhaps they can enter a few characters and you can then filter the list to entries that match, would make the search much less frustrating for your users and you as you won't have this limitation.
Just a thought