I know TIM in Italy released an official 4.5.52 like last month for the 8310 and there is another one floating around from Orange UK for the 8320. If I were you that's what I would go with, because its newer, an official copy, and there are way way way less bugs. You can find it on the bb forums with a link if you just look around for a bit.
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if you go to the forums homepage and select your model phone, the newest os will be sticky with a link in it for ya. and yes it is worth it to uprgade to 4.5.0.52