The Contour RollerMouse Red is a great piece of engineering besides being a boon to RSI sufferers. However, when dirt accumulates under the roller, the pointer's movement can become erratic. Cleaning it proved difficult, so I asked Contour for help. These are the instructions I received. I followed them to the letter and all was good again.
First, make sure the mouse is unplugged. Located on either end of the bar are two black caps. Push them inwards and you’ll hear them click. You should be able to pull them up and off now. Sometimes they can be a bit of a struggle, other times they come right up. Keep note which is left and right as they are specific to each side.
On the left side of the bar you’ll see a circuit board with a small ribbon cable attached, which is how the bar gets power. Be careful not to remove that. You won’t damage anything, but it can be difficult to set back in place.
Once the caps are off, you can slide the roller itself off the bar towards the right side. You may get some resistance to moving the bar as it is held in place by magnets. I will usually take this time to clean out the inside of the roller as well. I use some air duster down the tube and a qtip with some rubbing alcohol on the inner rim at each end. Usually cleaning it this way will reduce the resistance but, If moving the roller is giving you some resistance after it's been cleaned, you can apply some lubricant in a similar method. A teflon based lubricant is preferred as it's not as messy as oil, such as WD40. Though WD40 is definitely more common, and can be used as long as it’s a very small amount.
With the roller off, you’ve exposed the sensor, which is that lens in the center of the bar. Even if you can’t see anything on it, it’s very sensitive and the smallest particle in just the right spot may cause it to fail. Use some air duster and blow out the area around there and hopefully any dust particles will be removed. If you wanted to wipe down the bar, again rubbing alcohol would be fine, just try to avoid any of the components.
Now replace the roller bar, and replace the caps. The little outside "feet" on the bottom of the caps should line up with two small notches on the plastic part of the mouse and the smaller feet will line up right on the outside where the red/orange plastic ends. After pressing them down, make sure to push them outwards towards the ends. You should hear them click in place, or the bar won’t be set correctly, which can cause it to lose proper function.