No, no, maybe i said it wrong...
Lets call Folder A the folder where the androidinstall is in.
And call Folder B the folder where the update is.
you open the rom mix, you hit the add icon and select Folder A.
Then, you hit the button at the right (looks like a brown box with an arrow poinitng down) the one saying "Module update". If you press it, it asks for a working directory, and you put folder B.
You mix, save, and hopefully you are done!!
If you cant do it, i have a thread where i've put up a build, take a look.