Flickering app

Hello,

i have a problem with CAD 2.1.

This phenomen occurs primary at site of my client. I can reproduce it occasionally from my WAN-connection from home-office to the server:

After clicking around in a dialog the application is going unusable because the components are loosing focus and the hourglass is working frequently.

There are no timers. The HTML-Page is about 161 KByte.

Any idea ?

TIA
Regards
Ingo