Skritter seems to lose the connection to your servers whenever it needs to fetch characters, which makes it practically impossible for me to use it. I just see the animated three dots in the upper left corner of the drawing field and nothing happens.
I need to refresh the page and wait for quite a while and then I can do a few characters before the same thing happens again. Sometimes refreshing doesn't even help and I just need to wait a few minutes.
I notice this both on my arch linux OS and in a Windows XP VM. My public IP is 143.89.190.34, in case that's of any use. I also tried running skritter through a VPN (in Hong Kong) but I notice the same issue.