Unexpected error in JTAG Server

Last week I was able to detect the whole chain and program the devices. This week I have not been able to detect any of the devices in the chain. I am not sure what changed between now and then. I think it may be my USB Blaster, I have the initail release of the USB Blaster and the cable length on that programmer is long and may not be helping the problem. I have order new USB Blasters that should be here next week. Hopefully the flex cable on the lastest revision will help solve the problem however in the mean time I want see if there is anything else I can do to fix the problem. It may not be a signal integrity problem.