control alt and control tab

[Mr. B]

Guys/Gals,

I'm using the enterprise vnc viewer 4.5 on a mac running leopard  
(10.5).  I'm connecting to a windows vnc server running 4.4.

My problem is in passing special keys to the server.  Such as Alt -Tab  
to switch programs and Ctrl-Tab to switch thru windows in the  
foreground application....

I have set up the advanced settings such that the right hand apple  
command key translates to the windows key, that works.  I also set the  
left hand option key on the mac to be the alt key on the pc via the  
advanced settings.. that for some reason does nothing on the remote  
windows server.  Yet the left apple command key, which is  set for  
nothing in the advanced settings, is acting as the alt key on the  
windows server...  One important thing to note is that the control key  
on the apple does map to ctrl on the windows server, because i can  
copy and paste with ctrl-c and ctrl-v... yet ctrl-tab does not  
work... !!

Can anyone help me to get the option key to map to the alt key such  
that alt-tab will work... and that the control key will map correcting  
to make ctrl-tab work as well?  Or is this a bug...??

thanks
Vince