I have searched and cannot find anything vaguely similar so posting here in the hope I can find a solution

I am using the following:
Eclipse 3.4.2
BIRT Chart plugins are version 2.3.2
Adobe is 11.0.0.1 and there are no updates apparently.
I have 2 cross tabs and a bubble chart in my report. I run it in Web Viewer and it displays fine. However, when I export the report to PDF, the bubble chart is missing - everything above and below it is there, but a blank box where the bubble chart should be.
If you have a bubble chart that you managed to export to PDF fine, I'd love to hear from you.
Thanks.