First - SP06 for BPC 800 - is terribly old 
Same for BW 730 - SP05. There are some issues with aggregation fixed in the latest SP's. Recommendation - upgrade to the latest!
Second: Test report with only base members:
TIME: 2008.01
WB_ACCOUNT: 3RDPARTY
WB_INTERCO_FINAN: NON_INTERCO
WB_ENTITY: STORE1
WB_AUDIT: INPUT
CATEGORY: Actual
RPTCURRENCY: LC
Result?
Vadim