Don't know where the problem is. Maybe Report class is just for old qtf format...?
Yes.
This is one problem that has been left unresolved in 511, but it is fixed now (there is now new Report package, old Report class was removed from CtrlLib and placed to DocTypes as DocReport, DocTypes is now "legacy" package to support old apps and will not be distributed anymore).
The solution is to use latest snapshot. If you insist on staying with 511, there was intermmediate solution with PutQTF(Report&, const char*) function.