some body tells please what is the problem??

HQL code:
select sum(suggester.rewardPrice) from SuggestionDTO as suggestion join suggestion.suggesters as suggester join suggestion.councilOpinions as councilOpinion where councilOpinion.creationDate >= :startTime and councilOpinion.creationDate <= :endTime and councilOpinion.typeId == 1

error message:
"could not execute query\r\n[ select sum(suggesters1_.reewardprice) as x0_0_ from suggestion suggestion0_, SUGGESTERINFO suggesters1_, tcopinion councilopi2_ where suggestion0_.id=suggesters1_.suggestionid and suggestion0_.id=councilopi2_.suggestionid and ((councilopi2_.CREATIONDATE>=? )and(councilopi2_.CREATIONDATE<=? )and(councilopi2_.typeid==1 )) ]\r\n Name: endTime - Value: 10/22/2007 12:00:00 am\r\n Name: startTime - Value: 9/23/2007 12:00:00 am\r\n[SQL: select sum(suggesters1_.reewardprice) as x0_0_ from suggestion suggestion0_, SUGGESTERINFO suggesters1_, tcopinion councilopi2_ where suggestion0_.id=suggesters1_.suggestionid and suggestion0_.id=councilopi2_.suggestionid and ((councilopi2_.CREATIONDATE>=? )and(councilopi2_.CREATIONDATE<=? )and(councilopi2_.typeid==1 ))]"

inner exception:
"ORA-00936: missing expression\n"