Can you confirm that you are running bmake from the "MicroStation CONNECT Edition SDK" desktop developer shell - with Run as Administrator privilege's?
If that is the case or does not correct the behavior you are seeing you can run bmake verbose debugging using the following pattern: bmake +avilC myapp.mke > buildoutput.txt
Then review the sequential build output details starting by searching for all occurrences of "\temp" starting with the first and working your way back to what macro in what file and line number it processed to set it to that value.
HTH,
Bob