JQuery Form Submit Handler Doesn't Trigger When TextField Changes By Watin In MVC App?

I am writing Watin test in MVC Asp.net app. I mvc app, all input are wrpped with form and every time an input or textarea is changed their form gets submitted by jquery like code below:

$("textarea", context).change(function() {
$(this).parents('form:first').submit();
});

This is perfect when changes are done by keyboard. However this doesn't trigger the form submit when input/textarea are changed by Watin TypeText() method. I tried to call Change() and Blur() events by Watin and also tried PressTab() with no luck.