Since the Standard Client version 0.8 removed the full index of all historical transactions, some Bitcoin applications that relied on that functionality have stopped working. For example, one is no longer able to find out the sender of a given transaction by pure RPC calls. How can one access that transaction detail in the newer versions of the Bitcoin client?
Two new command-line or bitcoin.conf file commands have been added in the 0.8 release that allow for historical transactions to be accessible by recreating the old index:
txindex : maintains an extra index of old, spent transaction ids so they will be found by the getrawtransaction JSON-RPC method.
reindex : rebuild block and transaction indices from the downloaded block data.
you must run once with -txindex=1 -reindex=1 to rebuild block-chain indices