Hi Gary, something similar happened to me a while ago. I visited a site that automatically opened a new window as a popup, it was very small.

Then when I opened any new window in IE they were all the same small size which was really annoying. The way round it is to physically drag the window to full size from a corner, instead of hitting the maximise button. This way I found all new windows were maximised from then on etc.

Regards

Su