Rita,
If you wouldn't mind doing some testing to see if this can be solved one way or another would you be willing to download and try one or two other browsers?
Google Chrome is based on the same webkit Apple uses and it would be interesting to see if it suffers from the same malady.
You also might like to try
Camino that uses the same Gheko engine as Firefox, but to me feels a lot more
Mac-like.
