[ol][li]Does it make a difference whether or not you use the recycle bin?
[/li]
[li]If you view the same folder in Explorer, then do the delete as you were originally (using Opus), does Explorer reflect the change without a manual refresh?
[/li]
[li]If you haven't already since the problem started happening, try rebooting.
[/li]
[li]This FAQ may be of use.[/li][/ol]