i get the problem of my ps3 freezing alot after the dialog of a npc has loaded please help

[it yet again happens after long playtime on the game]

You possibly have some data corruption in your savegame, if you can, try earlier saves to see if they have the problem as well and if not you may have to lose the latest save or so and re-do.

Other than that doing a game and patch data uninstall followed by reinstall and making a new save point after loading your game, exit, reset console then reloading. Might help clean up the file as the reinstalled patch does a reset and cleanup on the gamedata.

HTH