Don't know if this bug was in the old file manager, but just ran into it with the one in MC360 1.01...
Here's exactly what I did:
Turn on the option "Hide Parent Folder Items".
Go into the file manager.
Go to C:
Hit the White button for the context menu, selected Make New Folder (in this case, "Junk").
Go to "Junk".
Hit the White button... nothing happened (I wanted to create a folder).
Works fine as long as ".." is showing ("Hide Parent Folder Items" turned off).
Edit: BTW, sorry, looks like I made the topic too long to fit.