That’s the first time I’ve seen this error, and all of your other pages seem to work OK. How were the two pages that the images link to created? Are they posts with the category of start or are they pages that have a parent page of start?
If you were to switch the theme to something like TwentyTwelve or TwentyThirteen, does the page appear when you click on the image?
I’m sorry to bump this old thread, but in my montezuma installation this error is occuring very, VERY often. How to repair it? I can edit php sources, etc.
The site is here: http://polskikursblendera.pl/