small indentation question
 

for some reason, vizard started showing blue lines before a beginning of
lines of code, signifying wrong indentation, eventhough the indentation is OKAY.
This also causes the script not to run, with an indentation error.
in order to fix it, each time i have to backspace and then space to the
same position, and this usually fixes it.
Why did this start happening? how do i solve it?
thanks!

is it possible that you are mixing whitespace and tabs?
this would make the code look correct, but as python recognizes the difference between tabs and whitespace, this causes indentation errors.

to see what is going on, under the "view" menu, switch "whitespace" on.