I was wondering if this a true requirement from Singapore so I searched.
http://www.mfa.gov.sg/internet/idx_foreignVisaFor.html2. Entry Requirements For Foreigners
All visitors to Singapore must meet the following entry requirements:
* Valid travel document (minimum validity = 6 months);
* Onward / return ticket;
* Entry facilities to next destination;
* Sufficient funds to stay in Singapore and
* Visa for Singapore (if applicable)