IAC iviews cache problem

Hi,

In my portal, I have few IAC iviews which calls backend ECC transactions on portal.

When i open a new browser window and use portal, it is working fine. but after i logoff and again login with new user in the same window, the IAC iviews shows the old user's data.

This is not the issue of portal cache as Welcome screen comes of current logged in user. But only Iviews show old user's data.

Please help how to resovle this issue.

Thanks.