Ahh, OK - thanks for letting me know. I have asked Alemba to officially log this as a separate issue with VMware so hopefully it does get fixed in FP5 as well.
As an aside, my alternative to putting a chart on the report was to put a Cross-Tab summary on instead. But guess what, when I do this, running the report manually it works fine, but when the schedule runs, the report that is attached to the email is completely blank...
I guess I will have to stick with having just the rows of data on the report for now and try and add a graph/summary on at a later date once it's fixed.