I have the same issue in Win 7 64bit with the latest version of Spark. I get 'Connection Failed' regardless of my settings in standalone mode or Pro Tools 9.0.3 and Sonar X1d. Pro Tools does not have 'Spark Private In' and 'Spark Private Out' listed in its Midi Input devices. Although Spark seems to be listed in midi devices in standalone mode, it makes no difference if it's selected and still fails to connect. The software alone works fine in all instances though.
In Win XP 32bit, Spark connects no problem. However, some of the beats/patterns tend to distort if they're a bit bassy and once this occurs, beats which didn't distort previously do too and I have to shut Spark hardware and software down to start afresh. This occurs in standalone, Pro Tools 9.0.3 and Sonar X1d. The software does this too without the hardware connected and I've used the onboard sound card and an Mbox3. Same in both instances.
I downloaded the latest firmware whilst connected in XP but nothing changed.