Solution : https://service.sap.com/sap/support/notes/1273778 (SAP Service marketplace login required)
Key words : 
component bc-srv-bsf-cur, converting fixed currency key figures, 100 conversion-relevant key figures, inconsistent datasource assignments, entered amount displayed, experienced system administrators, million data records, function module convert_to_local_currency, selected key figure, import support package 21
Related Notes : 
       
| 1274533 | Program RS_EURO_CONVERTER abends on DB6. | 
| 1231768 | Customizing for a country joining the Euro Area (Slovakia) | 
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| 1074388 | SAPBINews NetWeaver 7.0 BI Support Package 16 | 
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| 986893 | SAPBWNews BW SP22 NW'04 Stack 22 RIN | 
| 875986 | Note Assistant: Important notes | 
| 590370 | Too many uncompressed request (f table partitions) | 
| 579022 | Finding and deleting inconsistent DataSources | 
| 376976 | Euro conversion in the BW System |