If you own a copy of the first printing of the book, and you have found an error, then please check whether it has been corrected in the second printing by looking at the respective page in the following list:
p.009, p.036, p.044, p.056, p.093, p.094, p.112, p.113, p.125, p.126, p.127, p.128, p.131, p.132, p.138, p.141, p.156, p.158, p.167, p.168, p.175, p.179, p.198, p.206, p.208, p.223, p.235, p.243, p.252, p.272, p.274, p.279, p.282, p.284, p.295, p.306, p.323, p.362, p.365, p.379, p.436, p.455, p.478, p.483, p.487, p.499, p.523, p.546, p.551, p.583, p.586, p.589, p.590, p.599, p.609, p.xviiiIf your error is new, please email Bernhard Schoelkopf or Alex Smola.
PS: here's how you can tell whether you are looking at the first or the second printing: in the first printing, the last word of the Preface is "theory". In the second printing, it is "readers".