upgrade from version 5.0.45

[Marco Baiguera]

Hello everyone,
i am quite new to mysql and i recently begin to work with a company
who is using mysql 5.0.45 in production.
i think this version is too old and would like to upgrade to the most
recent 5.0.xx

my os is CentOS release 5.3.

is it safe to simply use "yum upgrade mysql" ?

are there any important differences i should be aware of between
5.0.45 and 5.0.77 ?
any diffferences in password encoding etc. ?

the db is properly backed up and replicated on two 5.0.77 slaves.

thank you
Marco