I'm not sure I completely understand your question . . .

Is your custom module using the DnnFilePickerUploader server control (DotNetNuke.Web.UI.WebControls.DnnFilePickerUploader) or your own implementation using an input html tag of type="file" and possibly the jQueryUI fileuploader wiget plugin?

If using the fileuploader wiget plugin, I suspect that you are not first calling the following methods in the module's Page_Load:

jQuery.RegisterFileUpload(Page);
jQuery.RegisterDnnJQueryPlugins(Page);

These are needed so that the proper jQuery plugins javascript files will be loaded. Since the ribbon control bar at the top of the page includes a file upload control which would already lrequest the above scripts may explain why the Choose File button is visible when the logged in user has page edit permissions and not visible when the user does not. 

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Bill, WESNet Designs
Team Lead - DotNetNuke Gallery Module Project (Not Actively Being Developed)
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