Hi Jan -
Instead of using the myCrosstab class, I just cut and paste the following from your initial post into the custom.css file :
.sapzencrosstab-DataCellDefault, .sapzencrosstab-HeaderCellDefault {
border: 0px !important;
}
.sapzencrosstab-HeaderCellDefault {
border: 0px !important;
}
.sapzencrosstab-TableDiv {
border: 0px !important;
}
and it seems to work the way you want. Maybe consider taking it out of the myCrosstab class like I did?