On the options bar at the top of the screen, click the arrow left of ‘weight:’, then un-check arrowheads.
Mathias
In your options bar: click on the downward triangle, that will pull up the arrowhead option – there you can turn it off.
– what Mathias said.
Not sure which version you’re using, but in PS7, there is a "custom shape" icon that defaults to an arrow. Make sure your tool is set to a straight line, and not that squiggly star. Click and hold on the tool button until the menu comes up, and hopefully that’ll help.
EDIT: Or, yes, deactivate the arrowhead thing. Good thinking!
– Nick
Thank you all so much. Problem fixed. Hopefully now I’ll be able to do my lightsaber. I hear the rotoscoping on PS is tedious work? Thanks.