Thanks for your response. Since posting, I've been playing with uploading images through the SMF profile instead of through CB. The images are automatically scaled without changing their aspect ratio. Therefore SMF is capable of taking images and scaling them appropriately.

I guess it might be a question of where the image transfer function in the bridge hooks into in the SMF core stuff. Which is way beyond my level of technical expertise, and probably counts as a Feature Request.

As an aside, I seem to be able to break SMF image upload if I try to upload very large pictures!