informix 出现 Database not selected yet,

informix 出现 Database not selected yet,紧急求助！！！！
数据库采用informix , 应用服务 采用websphere6.1(正版) ，jdk5.0 , 每天都会当机N次， 然后重启应用后过了一会还会当机，不知道什么原因？？？ 换了tomcat6.0 也是一样,所以不是应用的问题， 也不是数据库的问题，可能是 连接配置有问题，但不知道怎么解决？？？ 以下是报错的情况： （请高手帮忙，看看怎么解决，小弟先谢了！！！必有重谢，
小弟QQ: 15159909 ）

[09-6-4 13:20:01:848 GMT] 0000002e SystemOut O hql=select distinct pb.id, pb.projectType, pb.projName, pb.loanLimitForm, pb.projLoanLimit, pb.projLoanLimitBal, pb.status, pb.appstat ,ci.name from CoopProjBaseInfo pb, CustomerInfo ci where pb.custcd = ci.id and ci.custType = '2' and pb.projName like ? and pb.brcode = '0013' and pb.status = '0' and pb.appstat = '0' and not exists (select po.projectno from CoopProjApply po where po.projectno = pb.projectno and po.status = '0')
[09-6-4 13:20:03:466 GMT] 0000002e SystemOut O org.hibernate.util.JDBCExceptionReporter 2009-06-04 13:20:03,466 -- WARN -- SQL Error: -349, SQLState: IX000
[09-6-4 13:20:03:466 GMT] 0000002e SystemOut O org.hibernate.util.JDBCExceptionReporter 2009-06-04 13:20:03,466 -- WARN -- SQL Error: -349, SQLState: IX000
[09-6-4 13:20:03:466 GMT] 0000002e SystemOut O org.hibernate.util.JDBCExceptionReporter 2009-06-04 13:20:03,466 -- ERROR -- Database not selected yet.
[09-6-4 13:20:03:466 GMT] 0000002e SystemOut O org.hibernate.util.JDBCExceptionReporter 2009-06-04 13:20:03,466 -- ERROR -- Database not selected yet.
[09-6-4 13:20:03:479 GMT] 0000002e SystemOut O org.hibernate.event.def.DefaultLoadEventListener 2009-06-04 13:20:03,467 -- INFO -- Error performing load command
org.hibernate.exception.GenericJDBCException: could not load an entity: [com.huateng.ebank.entity.data.Loaninfo#gd200906030068]
at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:91)
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:79)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
at org.hibernate.loader.Loader.loadEntity(Loader.java:1799)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:93)
at org.hibernate.loader.entity.AbstractEntityLoader.load(AbstractEntityLoader.java:81)
at org.hibernate.persister.entity.AbstractEntityPersister.load(AbstractEntityPersister.java:2730)
at org.hibernate.event.def.DefaultLoadEventListener.loadFromDatasource(DefaultLoadEventListener.java:365)
at org.hibernate.event.def.DefaultLoadEventListener.doLoad(DefaultLoadEventListener.java:346)
at org.hibernate.event.def.DefaultLoadEventListener.load(DefaultLoadEventListener.java:123)
at org.hibernate.event.def.DefaultLoadEventListener.proxyOrLoad(DefaultLoadEventListener.java:161)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:87)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:869)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:788)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:781)
at org.springframework.orm.hibernate3.HibernateTemplate$3.doInHibernate(HibernateTemplate.java:490)
at org.springframework.orm.hibernate3.HibernateTemplate.execute(HibernateTemplate.java:366)
at org.springframework.orm.hibernate3.HibernateTemplate.load(HibernateTemplate.java:484)
at org.springframework.orm.hibernate3.HibernateTemplate.load(HibernateTemplate.java:478)
at com.huateng.ebank.entity.dao.LoaninfoDAO.query(LoaninfoDAO.java:53)
at com.huateng.ebank.business.loanapply.LoanApplyService.getBasicInfo(LoanApplyService.java:2451)
at com.huateng.ebank.business.inquiryprint.cqGetter.loan.LoaninfoGetter.call(LoaninfoGetter.java:50)
at com.huateng.commquery.process.call._CallGetter.process(_CallGetter.java:110)
at com.huateng.ebank.web.commQuery.BaseGetter.process(BaseGetter.java:50)
at com.huateng.commquery.process.call.BaseCallGetterProcess.processAsync(BaseCallGetterProcess.java:49)
at com.huateng.commquery.process.base._ResultViewProcess.processAsyncBean(_ResultViewProcess.java:587)