Not unusual for a DTP94 if you're attempting to profile a screen with white LED backlights, or a wide gamut screen. While it's an absolutely superb puck, it can really only handle monitors with a standard gamut and a CCFL backlight. Other possibilities... if you attempt to profile the monitor immediately after you've turned it on, you're going to get a lot of drift until the thing is full warmed up. I generally recommend about 45 minutes. The puck itself needs to warm up as well. Plug it in to your computer for at least 10 minutes prior to profiling. Also, make sure you do not plug it into a USB hub or USB extension (such as that of a keyboard or a monitor).