different memory reports across versions

Ive notived that xymon servers report memory usage differently across versions

eg 
4.3.12 reports on physical, swap
4.3.17 reports on physical, actual, swap4.3.28 reports on real/physical, actual/virtual, swap/page
4.3.30 reports on physical:, virtual:, page:


Are these simple differences between versions or is there some configuration Ive not come across before that is determining these ?
didds