The link below shows the cover to my months-old Cuisinart blender.
When SWMBO and I were searching the blender reviews, the only con we
found for the CBT-700 was the occasional reviewer who said that it was
very hard to put the cover on the jar. There were also a few responses
to those reviews where folks said that they never experienced that
problem.

Well, here we are, a few dozen smoothies later and it's next to
impossible to get the cover on the blender jar. We are lining up the
arrow on the cover with the spout as directed but it just won't go on
without very precise alignment and a lot of force. SWMBO doesn't even
try, she just holds the cover over the top of the jar as firmly as she
can. When brand new, it was a snug fit but now it's way beyond that.

In the spirit of full disclosure, SWMBO doesn't think that any of the
plastic parts should be put in the dishwasher (even though the
instructions claim it's dishwasher safe) but I have done it on
occasion. I wonder if that is the problem. The cover is either
plastic or a hard rubber so maybe the fins have hardened up so they do
not flex as much as they should anymore.

I called Cuisinart and they are going to send me a new cover, but she
read from the parts list and it specifically says "new covers will be
tight". I explained to her that tight is good, but "next to impossible
to put on" is not. I mentioned that the most common complaint on the
websites was about how the cover can be very hard to put on.

In any case, once I get the new one, I won't mind trying to fix the
old one. Please take a look at the picture and see if you can think of
way to modify the cover so it fits. Obviously trimming each fin with a
razor or sanding them down will work but I'm concerned about exposing
the "insides" of the fins. I really don't know if it will matter, but
the fins certainly won't have the "factory finish" once I trim them.
If that's going to cause pieces of plastic/rubber to flake off and end
up in my food then that's an issue.

So, here you go...have at it.

http://i440.photobucket.com/albums/q...8276203311.jpg

P.S. I've tried a little vegetable oil on the fins to make them
slippery and while that works to a certain degree, it's not something
I want to do everytime we use the blender.