I have the latest stable Community Builder Build and CBSubs4.0RC1 but no matter what I do the plan image will not show. I have tried setting this up with a donation and subscription, however no matter what I do it just shows a blank field. Not sure if there is a limit size on the image used, my image file is 250x70px, but I even tried uploading and using the one's here on this site, only as a test since they work.
Now in the Plan Image field under the Parameters tab this looked a little weird and not sure if this has an effect on why the plan image will not display.
Any Help is appreciated, I have read through the extensive PDF file and it looks to me like I have set this up correctly.