If the Rubber is bubbling then you possibly used a product on the boot that caused it or they are indeed defective, either way Kenetrek would have asked for you to send them in for evaluation, you would only be out shipping cost which is a bummer. Kenetrek run small for me and I should have ordered a half size larger. A pair of desert guides I purchased just did not fit me right and when I emailed them they were very personal and I felt I was dealing with someone that had my satisfaction in mind, they were stellar in communication with me and I could not have been more pleased with their service, simply amazing! If it were not for me having to eat the shipping cost of the boots to them I could not have asked for more.