I just attempted to import one of my SuperStar sequences, and the same thing, I don't think the x and y values are appropriate. I edited the 600 pixel tree Brian created. I am not wrapping, I have 24 strings of 25 pixels, starting from the bottom (will zig zag in the controller). I have several x values over 25, saw several in the 41 range.
Note, this sequence works fine as a data layer in xlights.
Just FYI, if you need any of the files, please let me know.
James