Master-master replication is asynchronous, hence it will definitely break if you write to both servers at once.
Even if the auto-increments are working, any other unique index and many other situations can break it - it's too brittle to be used.
But it is possible to use master-master as PART of a HA solution, you just need to ensure that applications only ever write to one of the pair and in a "clean" failover situation, e.g. admin failing over, it waits for the slave to catch up before switching.
This is not extremely difficult in practice, but a bit inconvenient.
Your main other option is to use DRBD, which is also not massively difficult to set up - but in this case, the 2nd machine is not even usable as a read replica - it just sits there being a hot spare. DRBD synchronously replicates the underlying storage, so everything is written safely to both machines.
There are some applications which are specially designed to tolerate the multi-master problems - these need to be designed VERY carefully with that exact situation in mind - in which case, it's ok. You can't use applications not designed for it though.
auto-increment is not the only, or the main problem.
Double check that your character sets on the databases and connections are what you expect them to be - your replication choking on a statement with a non-ASCII character is immediately suspicious.
Look at the master's binary log to see how the statement it logged is different from the statement that the replica is trying to execute - that will offer clues to the problem.
Sadly, you should also make sure that the versions of the server for both the master and slave are the same. I recently encountered a weird instance where we had bad SQL trying to update a non-NULL numeric column to NULL. In the version that the master was running, MySQL silently converted it to 0, but in the version that the replica was running, it was an error.
Also, instead of doing CHANGE MASTER to fix the replica, you should be doing
STOP SLAVE;
[correct and execute whatever statement is the problem]
SET GLOBAL sql_slave_skip_counter = 1;
START SLAVE;
http://dev.mysql.com/doc/refman/5.1/en/set-global-sql-slave-skip-counter.html
Best Answer
No, the Sybase replication server only works between Sybase instances.
Golden Gate software has an excellent solution for real time inter-database replication. You can set it up to bi-replicate, so that changes on each side are propagated.
http://www.goldengate.com