Hi Leslie, Though your problem seems solved, here is my tuppence worth on this subject. I had the same problem but for jumping from H2 to CO on our system (Delta-plus-XP) running Isodat2 when the software occasionally 'lost' the magnet position for CO (resulting in ??? in the gas configuration). My solution was to uninstall and reinstall Isodat and create everything from scratch using the Configurator. However, after some many crashes to novely wears off and with helpful hints from the boys at Bremen, I proceeded using the solution Anthony mentioned, i.e. creating a backup copy of the entire set of fully functional configuration and setup files in a separate directory, and just copy them into the right directory (after deleting the corrupt file) if the situation warrants it. So, what's new I hear you cry? Well, of late, my software crashes during acquisition near the magnet jump but without displaying a fancy error message. The system just freezes though the status indicator implies the data acquisition is still running. Only solution, reset / reboot of the PC. Checking the configuration files shows everything is as it should be. No nasty question marks but the correct magnet position is displayed. Several jump test runs show nothing untoward. (Before anybody asks, no, the PC only runs Isodat, nothing runs in the background or in parallel, and I mean absolutely nothing). For anything from 2 to 10 days the system behaves fine, only to crash again the moment one'sback is turned. So far, even the boys at Bremen are puzzled but, as Anthony says, a new SP has been released and the hope is this will cure this problem too. Regards, Wolfram On May 4 2006, Leslie D. Price wrote: > Anthony, > > That is the exact error that I am getting. I will back up all my data > and then use the backup program to see if it fixes it. Thanks so very > much, Les