Alt-Tab to Desktop and then to Dopus fails

Alt-Tab'ing between Desktop and then to Dopus fails to bring the Dopus window/lister to the front ... seemingly every other time.
I have to Alt-Tab to dopus a 2nd time to make the window/lister pop up.

Alt_Tab'ing between other apps and Dopus seems to work OK.

Dopus 10.0.3.4 64 bit win7 sp1

Probably the same as: Show Desktop / Windows Alert Sound