Use of gnome_execute_async and waitpid

[Spencer Buckner <bucknersa attglobal net>]

In a gnome application I'm using gnome_execute_async to start a child 
process which generates a file needed later in the program.  I've been 
trying to use waitpid to wait for the child process to finish.  The 
waitpid command returns -1 and an error message that says:
   No child processes
The code that trys to read the file generates an error message that says:
   Cannot open file <filename> (No such file or directory)
The file does get generated in the proper directory, but not in time for 
the code that needs to read it.

So, I don't understand the problem.  Do gnome_execute_async and waitpid 
not work together?  Is there a better way to cause the program to wait 
for gnome_execute_async to finish?

Thanks.