Looking at the 6500 itself, I see no errors or warnings.
What parameter is the Hardware Health Monitor looking at to generate this alert?
Is the a threshold that can be adjusted?
I bet you're experiencing a MIB incompatibility. I had the same problem with various Cisco products and SW NPM's default MIB. Check out this link and see if it answers / resolves the issue for you:
That seems to have resolved the problem.
Thanks.
