Rogers BB 9700 with Virgin Mobile SIM?

[fayebaby]

Alright, my sister has an Iphone 3g that she bought from Virgin Mobile and has a contract with.

She wants to buy a Blackberry Bold 9700 from Kijiji or Ebay. Most of the ones offered are from Rogers. Some unlocked.

So our question is this: Can you use the Virgin Mobile sim card in an unlocked Rogers Blackberry Bold 9700??

I've read conflicted things on the web, and I'm not sure at all. So if anyone knows, it would be greatly appreciated!!

Thanks for your time!

BTW we currently live in Ontario, Canada if location is needed.