Since PHP 5.4, $_SERVER['REQUEST_TIME'] includes microseconds, so it cannot be used any more directly with DateTime as it generates an exception :

DateTime::__construct(): Failed to parse time string (@1324373290.765) at position 12 (7): Unexpected character

This issue can be reproduced especially using REST as MvcTools uses REQUEST_TIME directly to construct the request date (see ezcMvcHttpRequestParser::processDate().

Yes, this is an issue to be fixed in Zeta components, but this can be easily and safely workarounded in eZ Publish.