I don't know without seeing your xls file. I get correct results
here opening xls with --sheet and --rowoffset specifications,
provide those specifications are right, i.e., in this case row 2
in sheet 2 contains variable names, starting in column 1, and
subsequent rows contain data.
You might want to check that the file doesn't contain "junk" off
screen to the right of the area you want gretl to read.