BUG #7500: hot-standby replica crash after an initial rsync

The following bug has been logged on the website:

Bug reference: 7500
Logged by: Maxim Boguk
Email address: maxim(dot)boguk(at)gmail(dot)com
PostgreSQL version: 9.0.8
Operating system: FreeBSD
Description:

Hi,

Reinitialization of the replica after failover is procedure performed by me
a lot times in that installation. And I never had any issues. But today
after following the same pg_start_backup/rsync procedure replica doesn't
start with following error:

2012-08-21 11:17:07.777 MSK 34329 @ from [vxid: txid:0] []LOG: entering
standby mode
2012-08-21 11:17:07.780 MSK 34329 @ from [vxid:1/0 txid:0] []LOG: redo
starts at 925/2C0004C8
2012-08-21 11:17:07.783 MSK 34329 @ from [vxid:1/0 txid:0] []FATAL: could
not access status of transaction 361788644
2012-08-21 11:17:07.783 MSK 34329 @ from [vxid:1/0 txid:0] []DETAIL: Could
not read from file "pg_multixact/offsets/1590" at offset 114688: Unknown
error: 0.
2012-08-21 11:17:07.783 MSK 34329 @ from [vxid:1/0 txid:0] []CONTEXT: xlog
redo create multixact 361788644 offset 822580965: 1768508061 1768508078
2012-08-21 11:17:07.791 MSK 34327 @ from [vxid: txid:0] []LOG: startup
process (PID 34329) exited with exit code 1
2012-08-21 11:17:07.791 MSK 34327 @ from [vxid: txid:0] []LOG: terminating
any other active server processes

I have kept all that database files for the future investigation.

What I should look into first?