build number:2.6.0.v20100601-1048

steps to reproduce:
1. get report in bug #311664
2. enable svg chart in preferences
3. preview in web viewer

expected result:
show background image

actual result:
no bg image shows.
it's should be a svg problem of firefox 3.5. there is no problem with firefox 3.6.
checked and no this issue in ff3.6, close it