_wtempnam returns NULL   

I have a test program where I call _wtempnam and it returns NULL. From the 
same command prompt, when I "echo %TMP%", it points to a valid directory in 
which I can create a file manually. When calling _wtempnam, I am passing 
"c:\\" for the directory path (which should be a valid directory). Any ideas 
on what's going on?

Thanks in advance

date: Wed, 7 Sep 2005 14:24:05 -0700   author:   Brett