attachment_fu && image caching

I have a little problem:

I'm operating with attachment_fu object (:storage => :file_system), for instance @image.
When I have to render it into the view, i'd like to use native helper <%= image_tag(@image.public_filename) %>, it generates the HTML code something like "<img src="/images/image.jpg?2342323">. I suppose that digits after the '?' is caching stuff. (?)
How can I get clean filepath?. Just now i constrained to be using 'The-Not-Rails-Way': i'm ducking pure html tags <img src="<%=@image.public_filename%>, thats a problem.

That is because my application logic needs to get in the next redirect action the renewed (post cropped) image, but not clean image path return me the previous image. Intresting that problem is actual just in IE and Opera. Safari and Firefox works just fine.