I've heard some reports from people who can't access pixeldrain because the host is down, but I can never find a trace of any downtime.
Often this can be resolved by adding ".direct" as a subdomain to the url, like this: http://direct.pixeldra.in/u/ZjPB_I. This method completely bypasses cloudflare, but the downside to this is that you can't stream files (list downloads).
I'm not really sure if I want to keep using cloudflare, the 100MB upload limit is also way too restrictive and doesn't fit my use case at all, so I have the feeling I should better ditch it soon.
If you've had this problem yourself would you please leave a comment? I want to see how serious this problem really is so I can judge is it's worth contacting cloudflare for, or if I should just disable it right away.
Disabling cloudflare does cause all the links using https to be broken, which is quite a problem, I'll have to look into getting a new certificate.