Take a look at that if you need info about updating.... I too watch youtube fine with OS 4.5.0.110 - That being said I dont see why you cannot if you are on 4.5, you should be able too...
You would not believe how much a quick read on the forums can help you out. Either that or a search.
Posted from my CrackBerry at wapforums.crackberry.com
Amazing isn't it?! LOL Now if there was a way to get everyone to read the 101 Lecture Series and Tips and How To's.........I guess there wouldn't be as much to post answers to on the forums if that happened.