Corrupted index, what do i do?

Hello,

today i restarted my postgresql 9.0 instance and it won't start.

The logs are
2012-01-12 14:01:59.976 MSK,,,5644,,4f0eaf97.160c,2,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"database system was not properly shut down;
automatic recovery in progress",,,,,,,,,""
2012-01-12 14:01:59.976 MSK,,,5644,,4f0eaf97.160c,3,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"consistent recovery state reached at
2A/7FA53250",,,,,,,,,""
2012-01-12 14:01:59.976 MSK,,,5644,,4f0eaf97.160c,4,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"redo starts at 2A/7FA53250",,,,,,,,,""
2012-01-12 14:01:59.999 MSK,,,5644,,4f0eaf97.160c,5,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"unexpected pageaddr 2A/8CE6000 in log file
42, segment 127, offset 13524992",,,,,,,,,""
2012-01-12 14:01:59.999 MSK,,,5644,,4f0eaf97.160c,6,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"redo done at 2A/7FCE5E20",,,,,,,,,""
2012-01-12 14:01:59.999 MSK,,,5644,,4f0eaf97.160c,7,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"last completed transaction was at log time
2012-01-12 13:37:40.810534+04",,,,,,,,,""
2012-01-12 14:02:00.040 MSK,,,5644,,4f0eaf97.160c,8,,2012-01-12
14:01:59 MSK,,0,FATAL,XX002,"index ""1339592"" contains unexpected
zero page at block 328134",,"Please REINDEX it.",,,,,,,""
2012-01-12 14:02:00.042 MSK,,,5642,,4f0eaf97.160a,1,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"startup process (PID 5644) exited with exit
code 1",,,,,,,,,""
2012-01-12 14:02:00.042 MSK,,,5642,,4f0eaf97.160a,2,,2012-01-12
14:01:59 MSK,,0,LOG,00000,"aborting startup due to startup process
failure",,,,,,,,,""

My question is corrupted index, not transaction rollbacks.
How can i rebuild index if db aint start?

I was running with fsync off, how postgresql behave about index
consistency with fsync on?

--
Evgeny