Plot scales going to strange values.

[GoogleCodeExporter]

What is the expected output? What do you see instead?
CPU usage plotted on a 0-100% scale. Scale is now -5e21 to +5e21, temperature 
is +/- 20 million.

What version of the product are you using? On what operating system?
0.7.1. Windows 7.

Please provide any additional information below.
When the scroll wheel is used to change the scale the min max values continue 
to grow and cannot be reduced making the plot useless.


Please attach a Report created with "File / Save Report...".
Cannot attach. "Issue attachment storage quota exceeded." show on submission 
page.

Original issue reported on code.google.com by [email protected] on 27 Apr 2015 at 11:49