So, if i am understanding your problem correctly, you are trying to duplicate your desktop at computer A on computer B. Are you able to switch between the 2 screens you are trying to access, or does it not allow you too?
Remote desktops often have issues with muti-monitor setups. Make sure your VPN client can support it. When I remote into systems with more than one monitor (which is often), I only see the main monitor.
I do know that "LogMeIn" allows you to at least switch between monitors so you can move back and forth as needed.
I don't think he's talking about moving between the local and remote views, but to have both monitors of the dual-monitor systems work remotely. Unless that's what you are talking about as well, or I'm not reading his question right.
There is someone in my office who has dual monitors and is able to use both of her monitors when she logs in. I've tried to duplicate how she logins using remote desktop, but I must be missing something. I just don't know what I need to check. I'm thinking it's something on my home computer since she and I have the same system at the office. Thanks for all the responses. I'll keep trying to figure out what I'm doing wrong.
It may not be that your doing anything wrong, but rather, a setting somewhere thats not correct. Check all of the settings you can find. Even if it doesnt seem like a likely place for some related setting to be. It could be as simple as checking a box next to "allow dual display's"