The SelectedFileItems property is available from code (and Intellisense), but it won't show up in the Properties View in VS.NET. In other words, code like this:
int numSelectedFiles = ftpConnection.SelectedFileItems.Length;
should work OK, even though you can't access the property from the Properties View.
The reason that it's not visible in the Properties View is that it doesn't have any meaning at design-time. In other words, there will never be any files selected while you're designing a form, so it doesn't make sense to show it.
Is that what you're finding? Or has something gone wrong with this property?
- Hans (EDT)