The strange thing is that about a week ago I could access the DVD-drive on my iMac (running Tiger) through the Finder on my MacBook Pro (running Leopard). That was from before the 10.5.2 update.
I could access the Age of Empires 3 DVD without a hassle. I only couldn't mount the drive completly because I wasn't able to start up my copy of AOE3 (by which you need the DVD in -your- drive)