Firstly, Welcome to GameBanshee!
Secondly, don't worry about your english, it's fine enough. Many of us here has english as second, third or even fourth language, so no worries there. As long as you at least try to use more or less proper english instead of things like "leet language", you are going fine.
And to your problem.
As far as I know, the problem occurs with the fact that the converter was meant to translate 1.00 version saves to 1.02 version. As your saves are 1.01, which is different than 1.00, the converter can't fully understand the saves and the error occurs.
Now, you ask if it's okay to run the game with normal 1.01 patch? I definately say no. Even though the it's possible to beat the game with such version, the list of big bugs is too long to describe and stay sane. And that only includes major bugs, not even close to all those minor bugs and annoyances. So, my suggestion is to upgrade to 1.02, but continue patching to as high as you can find patches to your language version. I think there should be patches for Italian version of the game beyond the 1.02 patch, but I'm not sure. The highest recommended patch is 1.05, which is fanmade. Though I honestly don't know if there is Italian version of it available.