Why do I keep getting "more than one canonical URL tag" on-page factor when, in fact, there is always only one?

[SmartWebPros]

The following are pages that SEOMOZ says have "more than one canonical URL tag" but they all have only one. Can someone help me understand this?http://www.lasercenterny.com/Laser-Hair-Removal-Binghamton/tabid/1950/Default.aspxhttp://www.lasercenterny.com/Hair-Removal-Binghamton-NY/tabid/1949/Default.aspxhttp://www.lasercenterny.com/Hair-Removal-Binghamton/tabid/1948/Default.aspx

[Nick_Sayers]

We will pick up that On Page error if the canonical URL tag is employed on two pages at a single time on an individual URL. So if www.awesome.com/index is canonicalized because it is the same content as www.awesome.com and I also put a relcanonical on that page then this error will show up. To ensure the search engines properly parse the canonical source, employ only a single version of this tag.

[SmartWebPros]

Thanks Nick, but I still don't understand how that applies to the pages that I listed. For each of these pages, the canonical tag is not on any of the other URL's.