I've found that if you re-size the graph/chart while in "powerpoint mode",
then these sort of things can happen.
It's always best to re-size the chart / graphi while in (graph mode)...I'm
sure you will understand what I'm rabbiting on a bout with this mode and
that mode?
I have the same or similar problem: create a chart in Powerpoint, in "graph"
mode the fonts (Arial) appear correctly and in proportion; as soon as graph
mode is exited, the fonts change appearance and become elongated or
compressed. This only started occuring with XP.