getJson() response text truncated

getJson() response text truncated

I'm using getJson() to call a web service that returns a very long json string.  like 350k characters.  the response comes back in its entirety from the server.  and i can see it in the net tab of firebug.  but the jsonp callback fails because the response text is truncated at character 28816. 

the only error in firebug is "invalid property id"
jsonp1269473615362({"d":[{"__type":"Client","ClientId":1,"AccountNumber":"11...
it's because the json string isn't terminated properly because it was truncated.  if i change the amount of data being returned to a low enough threshold, it works fine.

is this some sort of built in limitation?  it's not an issue with the max size of a javascript string.  so i'm not sure what else it could be.

thanks in advance for any information you can give me.