multi monitor/dual graphics cards/driver query

Hi,Realising that I was still running Catalyst 5.10 I thought it was about time I updated the drivers, so I downloaded and installed the latest 6.8 drivers and ccc. Problem, I have 2 cards installed, an X800 pro driving my main monitor and a PCI Radeon 7500 driving 2 further monitors, however the 6.8 drivers no longer support the PCI card so I downloaded and installed the 6.5 drivers which were the last to support both my cards. Question, is it possible and safe to have 2 sets of ATI drivers installed at the same time? ie the 6.8 for the X800 and the 6.5 for the PCI card.Many thanks for your help.Pete.