Dear Andre,
I didn't remember which version was. I went to application manager and then updating, there were 5-6 items for updating. one of them was Maemo 5 with 92.7MB, the file was downloaded after 7 hrs, then n900 was installing for 6 hrs but I couldn't get my phone. for example at this moment n900 is connected to my laptop but the laptob dosent know this device. On the screen of n900 shows installing softwear updating. Please do not interrupt.