I got the same issue upgrading from 11.8.0 to 11.10.0. I was about to start a new thread but decided to add my comment in this one since I found the answer for me and it might be related..
As mentioned earlier in this thread, after upgrading to 11.10, OPUS would take time to OPEN in dual mode (not too long but enough to notice) and reading directory would be very slow as I move from one directory to another using TREE. Now what I have found is this.
I have a single Button that display all MY CD Drive (V:Normal CD player W:Blu-Ray CD player Z:A Virtual CD created with Daemon TOOL.
The command for the Button is this one
Now I have observed that when I re-start window 7 x64 professional, with a commercial legal movie CD or Blu-ray already inserted, when I start OPUS, the LABEL of the CD's do not appear in my toolbar after the Drive's Letter and OPUS operate very slowly as if OPUS keep trying to read the CD already inserted. If I open the faulty CD bay and close it right away(still with the CD or BLu-ray insert using SHIFT to by-pass auto-start) , then OPUS display the label and stop running slowly. I don"t know if this was the case with Version 11.8 as I never had this situation of leaving a CD or BLUE-Ray still inserted while booting Window 7. This is the first time I have done that (holiday). So, I have try to re-start Window 7 many time with a CD or Blue-ray inserted and each time I get the same situation. OPUS open slowly and reading folder goes very slowly from any hard drive directory and the LABEL of the CD do not show up until I open and close the faulty CD player, then OPUS goes normally (very fast), no matter what I am reading or how many files in a directory. Any advice ?