As with most console games - the systems have a limited amount of HD (harddrive space) and you must free up space if the system is too full. This is the most common reason a game will not save properly on a next-gen system.
If you save it properly then yes it will.
There Isn't Enough Information In Your Question To Answer It Properly, But Uninstalling And Re-downloading Usually Works.
Yes, it does save. It also saves if you click esc.
Portal or Portal 2 mods on Steam is installed by first Downloading it and extracting it. Then copy the map file into your Portal 2 maps folder which is Run the game.
Yes and Portal 2.
Portal - 2002 Portal 2-21 was released on: USA: 18 November 2003
No, Portal is for PC only. Portal 2 is for PS3,Xbox 360,and PC. Plus it would suck on PSP.
Portal 2
Portal 2 comes out on April 18, 2011.
It will be on Mac the day Portal 2 is released.
To stop the autosave feature in Portal 2, you cannot completely disable it, as autosaves are integral to the game's design. However, you can manually save your progress by using the F6 key, which allows you to create a save point when you want. Be mindful that the game will still autosave at certain checkpoints, but manual saves can help you manage your progress more effectively.
Wait for Portal 2.