最新出版的《牛津英语用法指南》指出：

▲某些动词之后可以跟-ing形式（“动名词”），但一般不跟动词不定式。......后面一般要跟-ing形式的常见动词有：admit, appreciate, avoid, burst out ( crying / laughing), consider, contemplate, delay, deny, detest, dislike, endure, enjoy, escape, excuse, face, fancy, feel like, finish, forgive, give up, (can't) help, imagine, involve, keep (on), leave off, mention, mind, miss, postpone, practise, put off, resent, resist, risk, (can't) stand, suggest, understand

▲在某些动词之后，既可以用-ing形式，也可以用动词不定式。这些动词有：advise, allow, can't bear, begin, continue, forbid, forget, go, go on, hate, hear, intend, like, love, permit, prefer, propose, regret, remember, see, start, stop, try, watch 在某些情况下意思会不同，......

以上摘自《牛津英语用法指南 》第3版 第432；434页，外语教学与研究出版社2010年4月第1版

▲所以，我认为：postpone后接动词作宾语时，要用动名词，不能用不定式。