jQuery 1.3.2/UI 1.7.2 and jQuery 1.4.2/UI 1.8.2 in the same sandbox

jQuery 1.3.2/UI 1.7.2 and jQuery 1.4.2/UI 1.8.2 in the same sandbox

using sharepoint services 3.0 - the default master, as well as telerik rad controls include references to jQuery 1.3.x. I would like to standardize on 1.4.2 in my code for the reported speed enhancements and other functional improvements. Before I do, are there any known conflicts? How do I tell which functionality I'm going to see/use in my scripts? Is there a way to implement the jQuery.noConflict() between the two jQuery libraries?
 
And before you ask, I have no control on the 1.3.2 inclusion so it's got to stay. Might be a good time to bite the bullet and upgrade but not my call.
 
I've only been at jQuery for a month but looking good so far.
 
Thanks