What is the reason for font problems with R/3 - GuiXT?

In 3.1/4.0 SAP shows a different font size from the one the user programmed before. GuiXT takes into account the size the user set; that is why pictures do not appear at the excpected location. To solve the problem, choose a font size which will also be used by R/3 for viewing. The problem does not appear with R/3 4.5 or 4.6.