I've an application built using Sencha Touch 2.0.1
Recently I started notice that it wasn't working at all in UIWebView on iOS devices.
Other post on the forum suggested that setting the autoMaximize property to false could solve the problem but in my case it didn't help.
And it's really hard to debug UIWebView since we don't have any traces.
I'll try the new beta 2.1 release and I'll let you know if it changes anything.