help with Ruminate GUI and Rotation

[creative_m]

Hi, I want to make a small game,but I need help with Ruminate GUI (XNA 4.0).My question is how to put buttons in a panel that appears when the course goes over its location - let's say on the left of the screen.
I have written some code but I faces some troubles when this statement execute

gui.Draw();

the models in my scene "turn" to the opposite direction,I mean when I use this instruction the models rotate 180 degree.

the second question is how to rotate a mesh (or a model) around a line (not an axis).
I highly appreciate your help.
tanks in advance.

[ddanbe]

On a screen the x coordinate moves from left to right.
The y coordinate moves from top to bottom, so you could say it is rotated by 180°