'Take control' button in remote assistance disabled/does not appear

The novice sends and invitation for remote assistance, and I accept (I
am serving as the 'expert'). The novice's desktop appears, but the
'take control' button does not show up on the toolbar. In fact, none
of the buttons on the toolbar show up.

I am using a desktop computer. However, when I use my laptop,
connecting to the same belkin router and westwind dsl modem, I get the
'take control' button when serving as the 'expert' accepting
invitation for remote assitance. I don't think the issue relates to
the settings of the router or the dsl modem.

Any help deeply appreciated, many thanks.
.