Comment 12 for bug 1167553

thank you for taking this bug up that quickly. it is indeed independent of 32/64bit, and solely depends on which mode names the graphics driver provides. (which driver is used could depend on the address length, though.)

if this can be fasttracked to the next ubuntu lease, please do so, and let me know if you need help providing a minimal patch.

best regards
chrysn
arandr developer and debian package author