I figured out a solution that works for me and I thought I'd share it in case anyone else has the same issue. The signout.aspx code did clear the cache, so I chose to add onto that code module. I modified it to read:
function _spBodyOnLoad()
{
try
{
document.execCommand("ClearAuthenticationCache", "false");
if (confirm('You are now logged out. Login as a different user? (Click OK to login or cancel to exit the browser.)')) {
url="xxx.com/.../Project%20Timesheet%20Entry.aspx";
window.location=url;
} else {
window.close();
}
}
catch (e) {}
}
The url for the calling page is stored in the 'back to site' link. It would be better form to use document.getElementByID to reference that. I believe the element starts with 'C100' - but you can view the page source to see exactly. There were other solutions I tried, one from a microsoft site for sharepoint support that recommended modifying the Init,js file - but for some reason that resulted in the login pop-up being called 3 times on the initial load and not clearing the cache on the Sign in as a Different User option. It may have to do with the way BP invokes the SP code.
I hope this helps someone down the road.
Courtney
