Apologies if this has already been mentioned, I wasn't able to find anything online about it other than when it was mentioned, and pretty much ignored, here (first post by centiva):
http://blogs.msdn.com/b/webdev/archive/2006/05/05/590585.aspx?PageIndex=270
Came across this issue when completing this lab: http://www.asp.net/web-api/tutorials/hands-on-labs/build-a-single-page-application-(spa)-with-aspnet-web-api-and-angularjs
Using Microsoft.AspNet.Identity.UserManager, and specifically Microsoft.AspNet.Identity.PasswordValidator.
With PasswordValidator set with the property
RequireNonLetterOrDigit = true
Passwords must contain a non-letter AND ...
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