I'm getting a lot of error 500 related to timthumb.php on my site.
After some time debugging, I realized that, if I access the URL directly, it would work:
However, if I keep refreshing it, and then let it load, it would throw error 500.
My images are intermitent, sometimes some of them load, some times not.
What could cause this kind of error? I don't see anything on the logs.