Update the firmware using the tool installer here and see if it resolves it.
The tool is English, the link is American but the firmware is universal.
...is this firmware (073.030.055.33800) an offical version? What about warrenty?
The problem is:
All trays do not remember costumer formats or DIN formats like A6 (148 x 105 mm), B4 (250 x 353 mm) after wake up or restart.
Over and over again we must redefine these trays.
At the moment our solution is:
1. Media format settings from DIN-format to inch
2. remove the black-code-card (sensor card) from back fo the trays
Yes it is official, if you have a contract with Xerox on the device you are welcome to call us, go to 2nd level support, explain the issue again and eventually get to the point where they will email the same link I posted which is hosted on Xerox.com, or you can just install it and resolve the issue.
Or keep waiting, possibly Fabio will see this and confirm that he has seen this issue on the firmware you are running (General release) as I am all but certain he has run into it before.