OK, Thanks.
For a quick answer, jump to the Update at the bottom and skip the part between the two --------- which documented the different methods I tried to arrive at the answer.
I found the link on configuring Yahoo Desktop Search filters and Quickview
[resource.dopus.com/t/tip-free-viewer-plugins/267/1)
I was able to improve the alt-tab-like issue by going to Preferences / Plugins / ActiveX Document and enabling Alternative open method.
However, when I pointed it the Mutiview Viewer Location to the Quickview filters which I happen to have, I noticed that the loading of the files in the View Pane was much slower than in the case of Norton Commander which also uses the same Quickview Filters. Norton Commander seems to be able to view the files much faster. The viewing pane shows the files instantaneously (practically no wait time.)
In the Dopus View Pane, I can see word (loading) appearing after the file name and the same file that loaded instantaneously in Norton Commander Quickview mode can take up to 6 secs (and the file was only a small excel file of 13.5kb.)
I wonder why ?
I tried to then point the Multiview Viewer to the Yahoo Desktop Stellant Filters. But the results were the same - ie much slower.
I thought I would then try the native Multiview.dll as the filters.
So in the Settings|Preferences|Plugins|Viewers Tab, I tried to point the Multiview Viewer Plugin to C:\Program Files\GPsoftware\Directory Opus\Viewers
But the OK button remains greyed out so I could not click it. ie the Multiview Viewer Plugin remain pointed to Quickview.
The conclusion was that when viewed with the "Activex filters in the Dopus Viewer Pane, the documents appeared instantaneously, but it did an unwanted Alt Tab until I used Alternative Open Method.
But that slowed things down.
Update :
I unchecked the ActiveX Document Filters and guess what, the documents opened in the viewer panes INSTANTANEOUSLY. And no unwanted Alt Tab Problem.
WOW !!.
Since I already documented the problem, I will just post the solution for those still pulling out their hair like I was until 2 minutes ago.
I guess Dopus was trying out the two methods and that slowed things down.
