CSRF attack

prejudice to the forum I did a search on forum but I only found this:
www.joomlapolis.com/forum/154-advanced-members-support/152123-csrf-attack-angriff-erkannt- # 152214
Some users of my site made ​​with joomla 1.5.22 with the addition of Italian uddeIM when trying to send a PM receiving a box placed under the name of the recipient "intercept CSRF attack"
you know what that is?
how can I fix this?
Sorry for the English
thanks

It is explained in the FAQ.

Switch it off in the backend.

thanks to the speed of response other than "supermen"
I will read the FAQ and the ability to turn off the control csrf but first I'd like to understand the problem, it depends on the site or the browser user, and what might be the solution

The feature was added for J1.0 sites. J1.5/1.6 do not really need this protection. If enabled it works usually fine but when a user uses back/forward buttons it fails of course and it may interfere with other components/modules.

then advise me to disable it?
ok thanks