Specifically, when using my Win 7 x64 machine via remote desktop, occasionally, the Outlook ribbon does not draw properly. There are missing button icons or completely missing items that only appear after a mouse hover. The ribbon does not redraw if you move the window or minimize/restore it, so the buttons stay missing.
Another related symptom is in the email list window, when an item is deleted or a new item comes in, sometimes the list does not redraw via remote desktop. When you hover/move your mouse over the items, they redraw. This is particularly troublesome in that you could see an item that you'd like to delete but the item may actually be on the line below or the line above because the list did not redraw which makes you click your mouse on the WRONG item. The item does redraw properly when your mouse hovers over it, but it is easy to not notice this and you may delete the wrong item.
I haven't noticed these issues when working in Outlook directly, only via remote desktop.