Did this just recently start happening? The way downloads like that work is the web server needs to tell the browser what kind of file is being sent (image, program, document, etc). These are known as MIME types. If this information is not sent to the browser then it wont know what kind of file it is or what to do with it. If this just started happening then its likely something has changed on Rogers' end. You could try setting Safari to pose as IE, because Rogers may be specifically looking for IE when it initiates a file transfer causing Safari to not work properly with the process. It could also be a bug in Safari. Try another browser and see if that works.
-Macbook Pro 2GHz Core Duo 15.4", 2GB, 100GB, Superdrive, Airport, BT, 256MB ATI x1600