Is Mark Waugh's "Bubble Entendre" banned in the USA?

Two weeks ago I received an email informing me that an attempt to sell titles in my Semina series at the New York Art Book Fare had descended into farce because the books had been impounded by US customs. Book Works told me they'd flown from Europe to America to sell  the novels, but ended up manning an empty table. The publications have now disappeared and may have been destroyed; from New York any unsold copies should have gone on to a distributor in Los Angeles, but there is still no sign ...