I am running the latest win7 PNA-X firmware of A.10.49.11. The problem I am encountering is that when I try to perform a calibration on S-Parameter type channels by clicking the 'Cal Wizard' button, I get a strange error message of : "No such interface supported." (see attachment). It doesn't seem to have any issue when I try a non-S-Parameter channel such as SMC. I was able to repeat this error on all 3 of the PNA-X's in our lab. I don't get any error message when I click the 'Cal All Wizard', so I'm currently using this as a workaround. If you can confirm this behavior and resolve it at your earliest convenience, that would be greatly appreciated.