Caching issue in xMII

We pass values from one page to another using session variable like:

setPropertyValue("appPlannedOrdersSelectListSite",selPlant);

We are able to retrieve this value correctly when the internet (IE) settings is to "Every visit to the page". When the setting is "Automatically", it gets the old values.

Is there any way we could force to load the page using the code, instead of having to change the all the client box settings to "Every visit to the page". ?

Thanks,

Sara