When using GridPanel controls and FileUploadField controls in the same page ,the IE6 Progress Bar still looks like its loading

[scaujwc]

It is very strange that when using GridPanel controls and FileUploadField controls in the same aspx file. IF the Store in GridPanel uses "<Proxy><ext:PageProxy",when the page reload or post back the IE6 Progress Bar still looks like its loading(for a long time) . How can I stop the IE Progress Bar?
Expert help please!Extremely grateful!

Page is structured as follows:

<ext:FileUploadField ... />

<ext:GridPanel ... >

<ext:Store ...>
                                            <Proxy>
                                                <ext:PageProxy>
                                                </ext:PageProxy>
                                            </Proxy>

..........