We Purchased 400 Radeon R5 240 cards installed in Win 7 Pro 64 bit on Dell Optiplex 3020s. These cards were on Dell's approved list. I'm running DP to monitor and DVI to projector. Randomly, you'll hear the hardware detection sound from windows, both screens will go blank, then reappear. I see the event logged each time this happens: Failed:ADL_DisplaySLSBuilder_Get and return value is -1. This event is followed by around 10 other related events every time. I've updated drivers, changed settings, changed hardware, all with no affect so far. Using a different card is not an option, as we just bought 400 of these last year. Any ideas, please advise. Thanks!