caching issue on server

I have one live site.The issue is of caching.I get caching error in every 2-3 days.In order to resolve this issue I need to reset IIS of my server using iireset command.But this solves the issue temporarily .As error comes again after few days. The error comes on few开发者_C百科 pages not on the whole website.I have used caching in order to load |Country,state and city in the drop down list. The same deployed copy was working fine on the old server but after shifting it to new server this issue has got started. So I guess some setting needs modification on server.But unable to trace the exact issue. Pleas help me in doing this.