I am having a similar problem. Have a toughbook that I was able to install ACAD 2006 on. However, the right click option is dead, as in does not even act like I am clicking anything, unless I am over a toolbar. Then I get the properties and options to customize and the whole nine yards. The right click option's is all set up for old school behaviors (last command, enter, etc...) but I still get nothing.
Any ideas!?