I am not familiar with your drive, so i dont know its overburning capabilities first hand. Taking it that you've overburned up to 90min before, i guess it can go that far.
You can not overburn with tao, both dao and dao/96 should be ok for overburning though. As BadReligion already mentioned, plain dao will just fine. You should get no coaster due to this parameter. Are the media you're using capable of handling overburning?
Just do an overburning test with Nero CD Speed and see how far it goes. Theres no reason why it could do overburning in the past and not now, other than media. It would be better to use the latest Nero and firmware for your drive.