I got my 510 about 10 days ago. I finally started using a second atty. The first atty was just the metal. This 2nd one has the metal band and a white band crossing it like an X. My first atty I could just take the cart on and off without any hassle. This second one though it fits so tight I have to yank the cart off with my teeth. So hard it leaves marks in the cart. I've aligned it to the metal. Is there something I'm doing wrong or is this just the way it is? My first atty was a dream. This tight fit is just so &#%* aggravating considering how often I have to top off. I have 2 other attys I haven't touched but they are also X'ed. Whats the difference? Is there a name for these vs the ones with just the metal? If so I'd like to know it cause I want just the metal ones. I've heard mixed results with taking the wicking out. So, I'm not going to do that.