When not to use Polarizing Filter ?

I'm still learning the basics and I have become aware of most of the advantages of using a Polarizing Filter.
But my questions is when does the filter start to work against me.
When should i NOT use a polarizing filter ?

Thanks in advance for any replys.

TmcG
Albany NY

http://www.pbase.com/t​mcg

At the risk of stating the obvious, you shouldn't use a polarizer when it's too dark. A polarizer will cost you about two stops, which can lead to camera shake blur.

Sometimes, when adjusted for the maximum sky darkening, it can actually make the sky unnaturally dark. This is of course a matter of subjective taste.

One use you may not have discovered yet is related to the fact that a polarizer acts like a neutral density filter. This can be handy for daylight fill flash, when the 1/250 shutter speed limitation can be a problem in bright light.

I find that a polarizer might not be appropriate for panoramas because you get a dark section of the sky. For example:
http://img.groundspeak​.com/cache/log/585640_​200.jpg

If you do use one for panos, make sure you don't adjust it between shots.