ixwood's suggestions are good ones; I'd suggest the latter. No need for multiple calls.
per the documentation, the function really just does some "screen scraping" under the covers, grabbing values from /_layouts/userdisp.aspx?Force=True. I'd suggest looking at that page for the user(s) where you are having troubles and making sure that there are in fact values for the fields you need.
M.
per the documentation, the function really just does some "screen scraping" under the covers, grabbing values from /_layouts/userdisp.aspx?Force=True. I'd suggest looking at that page for the user(s) where you are having troubles and making sure that there are in fact values for the fields you need.
M.