I newly purchased Omnisphere, installed all the six dvd:s, opened Sonar X3d, inserted Omnisphere and started to play around.
First the synth played like a charm. Then, suddenly it stopped working although Sonar received midi-signals. A mouse click on the internal play button in Omnisphere still produced sounds. Tested Dim Pro and Alchemy, both worked allright. Changed the channel output in the Omnisphere midi track (c) in trackview from "None" to "1:Omnisphere" and the synth starts playing sound again. Fine! Then it suddenly also became possible to simply browse through different sounds by pressing the up and down arrows on the computer keyboard. After that I changed the midi output back to "None" (from "1:Omnisphere") and the synth still plays! But now the up-and-down-arrow-browsing doesn't work any longer. I don't get it... Do you?