Hi,
After a further research I have found following interesting info in SAP Admin guide about load balancing and web services
http://help.sap.com/businessobject/product_guides/sbo41/en/sbo41sp4_bip_admin_en.pdf
Web Services applications are currently only supported with the following load balancer configurations:
1. Source IP address persistence.
2. Source IP and destination port persistence (available only on a Cisco Content Services Switch).
3. SSL persistence.
4. Cookie based session persistence.
We already set up F5 load balancer to manage cookie based session persistance to manage BOE app (I have not found any info about BOE load balancer support in the admin guide but our test demonstrate that it is required), but with this configuration only QaaWs does work (no support to Crystal Reports 7 Design studio / BI services). Maybe we need to use another load balancer configuration in such a case. We will test it soon.
Thanks,