zoom selection not being full respected in ensuing zoom

[<pl...@pi...>]

Hi,

this is something I notices about 6 months ago. Don't know if it was a 
regression or I had never noticed it before.

If I select a zoom area with the mouse, the top , bottom and right hand 
coords are used but it does not always seem to catch the left hand one.

I think this is happening if there are several plot lines.

I have a plot with six lines showing this oddity but one with four that 
does not.

I have had a college report the same thing on windoze builds.

If that does not make sense I'll try to narrow it down a bit more.

regards, Peter.