Slow refresh on PC (fast on Mac). Bug ?

[carlocas]

We have developped a fairly complex solution to help manage restaurants called BC Resto.

Our main layout displays several portals linked to different tables.

Unfortunately we are experiencing severe slowdowns when our program is used on a PC :

On Windows XP, whenever we change something on the screen (adding a record, modifing a field and commiting for exampe) all of the screen redraws (even on top of the line brand new PCs)

On the Mac, only the modified portal/record/field redraws.

Is this a BUG ? Is there a way to change the way Filemaker redraws the screen ?

Could someone attending devconf ask a Filemaker engineer what is going wrong ?

You can download a demo of the file here :

http://www.bmonaco.com/download/bcresto.zip

Thank you