Please post code that allows us to accurately reproduce your problem. This means, post code that inserts a fresh row and then tries to update the values, and then checks that they have changed. Otherwise, if you do not want us to ask you questions that you are really, really sure do not apply, make sure you have tested them already, and tell us that you have tested them already, and even better, show how you tested these.

At least from your Perl code, it is still unclear to me why the code you showed would not work, so I assume that the error likely is elsewhere, either in your testing method, in the database or in the code you didn't show.

First of all, I would like to apologize to all for my previous sharp answers, but... I come from three days of debugging in a very large code, in order to discover the error.
And your first answers sound to me like "you are beginner, please learn SQL and DB management before asking"... not a great answer to have, after serveral days of hard debugging...

So excuse me for my previous roughness.

Then, I answer to Marto:

We aren't sure of anything.
Me too.. :-) so we are all Socratians... :-)
I'm asking to you, because I think you are more experienced than me... I thought that problem maybe occurred to something else and so I asked :-).

By the way, I think that is a very serious bug, and it affects many Red Hat versions (see below)...
So I thought it may be occurred to someone else.

if I will know the solution, I'm not be here to ask, but maybe to answer to someone else...
:-)
Did you check the change log and bugs relating to this old version of the module?
yes.
Maybe it is something like this:
Fixed DBD::Proxy handling of some methods, including commit and rollback.

Are you using the system Perl which shipped with RedHat?

I'm using the system which is shipped with CentOS 5 (Red Hat re-compiled for the community): it follows the Red Hat updates.

To Corion

Also, you could install a newer version of DBI yourself, as a test to check whether the error goes away.
Yes I will try via CPAN, before asking to sysadmin to update the package.

I was suggesting that you do the research, given that I don't know off the top of my head, it's your job and I have my own job to do. I dare say that someone has experienced this problem before, but I've not super searched or searched google to find out for sure.

Sounds like you may have a really old version of Perl to work with too. You've been given advice previously about this from Corion.

thank you for your answer,

In my original post now I inserted an update, as you asked me.
I tried the same code on another machine, with DBI 1.615, and all works fine.
I think it is something related to DBI 1.52.
Unlikley DBI 1.52 is the default package on Red Hat Enterprise and CentOS.

Any suggestions?

DBI 1.52 is from 2006, see the Changes and consider upgrading.

thank you for your answer,
now it is a system problem,
because DBI 1.52 comes with main Red Hat Enterprise version.

If I will update the package outside the core distribution, will not be so simple to update the system (via yum).

Anyway
Are we sure that the rror is in old-DBI-version?
Thank you

Upgrade your OS, or ask your OS distributor to fix the issue. If you are unable or unwilling to upgrade, there are no other options.

Also, you could install a newer version of DBI yourself, as a test to check whether the error goes away.

"Are we sure that the rror is in old-DBI-version?"

We aren't sure of anything. Did you check the change log and bugs relating to this old version of the module?

Are you using the system Perl which shipped with RedHat?