Device won't programme - JTAG error

hi

I hope this is the correct forum for this question.

A while ago I bought 3 Altera development boards in an auction with the EPM1270F256 CPLDs on them.They came with Altera ByteBlaster cables. Using Quartus II I managed to get the demo programmes loaded and working on all of them.

Then I bought a cheap CPLD board with an EPM240F100 chip and a USB Blaster, which I've used successfully for a couple of weeks, but the number of resources it has limits the programmes I could write.

So yesterday, I went back to the EPM1270 boards and tried to programme them with the USB Blaster. I got a JTAG error message saying "incorrect clock value" on all 3 boards, and got the same message when I tried with the ByteBlaster cable, which used to work. I wondered if I've accidentally done something to Quartus since using the USB Blaster that has changed some clock somewhere and I need to change it back so that JTAG works with the EPM1270 boards.

I can't find anything on the internet offering a solution to this, can anybody here help ?

regards