Hi,
Whenever I start my system all other autorun programs start in a snap, but
DO takes litteraly MINUTES to get the icon in the systray, and be ready for input ?!?
I watched the startup using Process Monitor and see DOpus accessing/reading/writing hundreds of thousands registry entries and file accesses ?
Please why does this program take such a horrible long time to start ? 
Clear out any old, unused Collections and uninstall any unused Icon Packs (Preferences - Display - Toolbar Icons).
Also, if you have toolbars open in Opus which use lots of external icons, like a big toolbar with buttons that run lots of other apps where all the icons come from those apps, then that will force Opus to read in all of those icons at startup which can take a while when the machine has just booted, since so many other programs are all accessing the disk at the same time.
Those are the things I can think of but maybe there are more.
The other thing to keep in mind is that just because other programs have become visible it doesn't mean they are responsive. Just after boot I find all my windows machines can be quite unresponsive for a while because programs are still starting up, or Windows Update and virus checkers are doing a lot of stuff because they haven't run for a while, etc., and if I try to use anything it is sluggish.
I get the impression that Opus loads everything it needs up-front and then starts showing its windows, so once you see Opus it's responsive. I don't know if that's really true or just how it appears on my machines with my Opus configuration, though. Maybe it's different for other people.
OK, Thanx Leo.
I didn't have any collections, but unloading Icon packs, and removing some of my program shortcuts has improved loading times. 