Cards are not always working when presented. They work most of the time but then will not for a short time. I had spoken with tech support and they informed me of a problem when the omni pro ll is connected to a gigabit network it could create a problem. I disconnected the system from the network but it did not correct the problem. I replaced all components and wire but still have the issue. The other reader on the system works fine. Hopefully someone will have an answer.