Links to non-existent files crash memory with MAMP on a Mac

I bought a new MacBook Pro laptop last spring. I was disappointed with the way it handles memory, especially with browsers. But I got by - until recently.

A few days ago, my memory began spiking, almost crashing my computer. An Apple tech helped me track the problem to Apache - the one bundled with MAMP. He checked a system log that showed a page crashing because it's linked to a CSS file that doesn't exist. Most of the memory freezes result from links to non-existent images.

I should mention that I've been upgrading my websites, with many changes. I've changed all my URL's to lower case, with underscores replaced by dashes. So a link to World/New_York is now world/new-york. That's why I have so many pages with bad links (which I'm fixing as fast as I can).

I modified Apache on my online web servers so that links automatically default to lower case with dashes. I think I made the same change on my computer, though I have to look through my notes to remember exactly how I did it.

But I think things were generally OK until recently. I noticed this specific problem just a few days ago. I thought it might be the result of some software upgrade. However, I upgraded MAMP just today - AFTER the problem began. The upgrade didn't fix it.

Anyone, have any of you experienced this problem with Mac / Mavericks / MAMP Pro? Do you know how I can tell Apache to ignore links to non-existent files and stop crashing my computer? If there's a way to tell Apache to show a warning, that would be great. But I don't have time to battle my memory 24/7.

Thanks.