RooFit: filling dataset from the TTree with structure

Hi,

I'm using root5.26b and I have problems with filling dataset from an existing TTree.
The macro which illustrates the problem is attached (it's derived from on of roofit examples).

The problem: when a TTree is created with a TBranch pointing to a structure, the dataset is filled with copies of the only one number. The structure used contains only three doubles ( tree->Branch("xyz", &pxyz,"x/D:y/D:z/D") ). The RooRealVars have names with the full names of the leaves (i.e. "xyz.x" etc).
X and Z are filled with the "gaus", Y is filled uniformly.

rf401_importttreethx(true) — Creates the branch pointing to the structure, then fills the tree, fills the dataset and draws it. rf401_importttreethx(false) — Creates separate branches for each variable. It shows the desired behavior.

Is there any naming error in my example, or, maybe, it's not suposed to work in such a way?

best regards, Maxim Gonchar