any one have a solution for this..
WARNING: This can be resource intensive on sites with large number of items!
may be its helps you in joomla2.5 purge cach warrning
http://docs.joomla.org/Help25:Site_Maintenance_Purge_Expired_Cache
http://www.inmotionhosting.com/support/edu/joomla-25/caching/clear-cache
http://brian.teeman.net/joomla/774-upgrading-to-joomla-2-5-some-warnings
read it and try it...