If I do any actions like sorting at http://www.sencha.com/examples/#Exam...motefiltergrid
most of the time the first RPC fails with HTTP 503.
Even clicking the refresh button several times leads to nearly every 2nd call to fail.
Attention: to realize a failed call u have to look at "Net" Tab of ur FireBug or Wireshark the connection, etc. since the example doesn't tell u that a call failed.
I do not know if this is due to our network, your server or a bug in client- or serverside code. I should try from home. Can some confirm my observation?