Yosemite Mission Control Issue

Hello Everyone,

I am having an issue configuring Mission Control on Yosemite.

I have a 3 monitor setup, including my internal from the macbook, an HDMI and a VGA connected to the thunderbolt.

I tried different configurations but in every case every time I reboot I find myself with a different number of desktops, different wallpapers (as changed between screen) from the last time. This is pretty annoying and I have yet to find a solution to this.

These are my actual mission control settings:

Thanks in advance,

Leonardo