Hi Roger
I'm going to throw in several suggestions. Hopefully, one might help.
Does this occur in the Editor, Preview or when Published?
If you set the properties to index the words on a page, then Preview and run a pub search, this can take forever.
Are you using Vista? I've have a couple of colleagues who are blaming Vista for slow performances. I can't comment because Vista is a long, long way under my radar.
What are your resources like? Have you recently installed new hardware/software?
At the risk of being impertinent
can I ask if:
1. You've checked for viruses and malware?
2. Defragged your drives?
3. Checked the state of the Registry using something like CCleaner?
Given your experience, I'll be surprised if you don't do this regularly.
Try turning on the Windows Task Manager and checking the Applications, Processes, and Performance Tabs to see if all looks OK.
Rarely, when I've had unaccountable processing issues, I've checked for new drivers like display, for example.
Could you be using an external HDD that has been daisy-chained from a printer or scanner? I recently solved a speed problem by unplugging the HDD and attaching it to a powered hub. I was assured by someone who knows a lot more than I do about these things, that daisy-chanined peripherals can drop from USB 2.0 to 1.1
Have you or would you consider doing a clean reinstall of Opus?
HTH