Working with BIRT (Business Information Reporting Tool) - Eclipse based.

It reads/writes out  memory variables but inconsistently.  If you do NOT have more than one report line it won't / doesn't seem to want to write them out from the report footer.  Thinking if row_count=1 perhaps?  I could write out the memory variable from the detail 'render' line?

Where is the BIRT object model to be found??