[other] Photoshop with Virtualbox

Hello

I have virtual box 4.2 (64 bits) with photoshop cs5 It's works but I have a little problem with buffer, I can't use this (alt+clic) I have message "impossible to use buffer" etc...
I've already search on web to find the problem, perhaps it's a command on virtualbox or over witch use alt and apparently it do conflict with photoshop

someone have an idea?

thanks you