Hi,
Don't let this discourage you, but the thing I don't like about many reports implemented using OO most is that I have to scroll up and down countless times just to figure out the flow of a trivial report.
lcl_data->select_data( ) is not utilizing rs_vbeln but rather s_vblen... oh, the "power" of global things 
I cringed looking at the all public lcl_data (don't really know why) and the FOR ALL ENTRIES...
Maybe it just takes some getting used to time, but I honestly doubt the utility of programming reports this way. This report will not support being SUBMITted and being planned as a SM37 batch job, will it?
cheers
Jānis