OAF Customization requires cache clearing each time a user logs in to see the change

Hi,

I did a OAF customization in iExpense module to restrict the iE templates as per each user's zone (we have the same templates for each user zone). The customization is working fine, but it picks the previously logged in user's zone when another user logs in. we are having to clear the cache after one user is logged in otherwise it doesn't pick the current user's zone. Once the cache is cleared it picks the current user's zone. Can I know the reason for it and how to resolve it.

Thank you,