Qt image viewer simple modification

I have a Qt (QGraphicsView, QGraphicsScene, and QGraphicsPixmapItem) project that simply loads image from file, and add it to the qgraphicspixmap item. you can zoom in/out the pixmapitem using setTransformation() function. Its very basic program, and it works extremely well under Windows, but under Linux, if I open the a large image (over .5 mb) and load it in full size it works OK, if I change the zoom either in or out, it becomes apparently slow (the mouse movement, and the scrolling of the pixmap) I need to see if anyone has any experience in fixing this, or can give me a valid response why this is NOT working correctly, and how to fix this. I believe this should be very simple problem for someone who know what they are doing and should not take a lot of time to figure out the solution. I will be waiting for your bids and feedbacks Best regards, ## Deliverables the source code is writing using Qt 4.5, I will provide source code for interested bidders, and I'm open to any suggestions and comments. * * *This broadcast message was sent to all bidders on Wednesday Mar 17, 2010 8:19:43 AM: please ONLY developers who worked with QT before and understand this problem