I'm not certain, but it may be that the database needs to have flow data AND cbQoS enabled for it to appear in the views? Looking at the NTA instance I'm supporting right now, the only nodes that have cbQoS enabled have netflow enabled also.
Only an official SolarWinds boffin can answer that, however, so hopefully one of the usual suspects will appear and help soon™!
I opened a support case after talking to SolarWinds, it looks like an IOS version issue. It appears there are IOS versions pre 12.4(4)T that support CBQoS, but don't appear to support SNMP polling of CBQoS data.