To reproduce:
1. signup as a new user
2. then click the pages report link on dashboard

Strangely enough, if you are persistent, and re-login (1 or more times) as the same user, the NPE will go away. Maybe that might shed light on the problem.

java.lang.NullPointerException
at net.sf.hibernate.proxy.HibernateProxyHelper.getClass(HibernateProxyHelper.java:36)
at net.sf.hibernate.impl.AbstractQueryImpl.guessType(AbstractQueryImpl.java:390)
at net.sf.hibernate.impl.AbstractQueryImpl.setParameter(AbstractQueryImpl.java:385)
at com.atlassian.confluence.core.persistence.hibernate.HibernateObjectDao$4.doInHibernate(HibernateObjectDao.java:291)
at org.springframework.orm.hibernate.HibernateTemplate.execute(HibernateTemplate.java:149)
at org.springframework.orm.hibernate.HibernateTemplate.executeFind(HibernateTemplate.java:473)
at com.atlassian.confluence.core.persistence.hibernate.HibernateObjectDao.findNamedQueryStringParams(HibernateObjectDao.java:283)
at com.atlassian.confluence.core.persistence.hibernate.HibernateObjectDao.findNamedQueryStringParams(HibernateObjectDao.java:268)
at com.atlassian.confluence.core.persistence.hibernate.HibernateObjectDao.findNamedQueryStringParams(HibernateObjectDao.java:248)
at com.atlassian.confluence.core.persistence.hibernate.HibernateObjectDao.findNamedQueryStringParam(HibernateObjectDao.java:233)
at com.atlassian.confluence.pages.persistence.dao.hibernate.HibernatePageDao.getPagesCreatedOrUpdatedSinceDate(HibernatePageDao.java:230)
at com.atlassian.confluence.pages.DefaultPageManager.getPagesCreatedOrUpdatedSinceDate(DefaultPageManager.java:91)
at sun.reflect.GeneratedMethodAccessor138.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)