if exists IMG click IMG gives FindFailed error

Hello,

I want to start by thanking those who help with my issue. I am very n00b to sikuli and love the potential of this IDE. I have a snippy go code which runs at one point to accomplish the following:

1) see if an image exists within a region
2) if it exists to click on the image
3) wait .3 seconds

here is my code:

if legregion.exists(Pattern("1397090049278.png").similar(0.47)):
        legregion.click(Pattern("1397090049278.png").similar(0.47))
        wait (.3)

Now the odd thing is it runs fine and produces no problems in situations when the image is present on the screen and when the image is not present on the screen in the first several loops of the entire script. But once it gets to ~10 loops, it produces the following error:

[error] script [ test ] stopped with error in line 117
[error] FindFailed ( can not find P(1397096048453.png) S: 0.91 on the screen. )

There are several parts of this problem that is puzzling, first why this can run several times (in situations where the image it's looking for is present and not present) for several loops and why does it product a FindFailed error when I am using "exists" instead of "find"?

Thank you for your help. In attempt to try to google a solution, I did find the following link, but could not decipher a solution from it: http://testautomationnoob.blogspot.com/2013/04/sikuli-script-troubleshooting-problems.html. Maybe it will help others.