Problem with sending Column Chart from UK to US
 

I've made a spreadsheet, which contains some charts, which gets sent
around the world (I'm in the UK).
I've had a problem with the s/sheet crashing on opening for some US
users, which I've traced to some 'workbook activate' code.
But I'm still having some problems with the column charts (line charts
are fine).
They've sent me screenshots, and instead fo a nice series of columns
they see some 'spidery' lines at the right and left hand ends of where
the chart should be. (the chart is set to have no axes displayed).

Anyone else seen this?
TIA
Dz