Fonts view weird when typing in 150% view

[AdiD]

We are running Pro7 (v3a) and are experiencing a strange thing with the fonts in some of our databases.

When typing in the 150% view (in Arial) the fonts sometimes start showing as obscure fonts i.e. not english!!...when dropping down to 100% the view fine (and if you go back 150% after that it is ok again!!)

Any ideas with font problems such as this or similar??

Cheers