I think that's "normal", the 2.7 doc[0] says:
"""
Changed in version 2.7: A comparison between a float instance x and a Decimal instance y now returns a result based on the values of x and y. In earlier versions x < y returned the same (arbitrary) result for any Decimal instance x and any float instance y.
"""

This means that in Python 2.6 a comparison between Decimal and float is a meaningless operation that might return arbitrary values.

[0]: http://docs.python.org/library/decimal.html#decimal.Decimal