MonoDevelop expected MonoTouch to be in System disc

I was frustrated when I tried to use MonoTouch (even though it's just the evaluation edition).  I followed everything properly to install all the parts, yet I still got error saying "iPhone 4.0 SDK was not installed".  After reading this post, I suddenly started to wonder if MonoDevelop was expecting iPhone SDK and MonoTouch to be both installed on OS drive.  Sure enough, I found the MonoTouch folder inside the Develop folder on OS drive.  And after I removed that folder, MonoDevelop didn't recognize the existence of MonoTouch.  This is lame to me, since my Develop folder (with iPhone SDK) is actually on another drive, and I am NOT gonna move it just because of stupid MonoTouch.