sleep() hangups

hi

I'm hopeless and I'm out of answers again.

I'm currently porting a very badly written program in C to my embedded Linux
box with NGPT 2.2.1  The program is filled with threads and sleep statements
all over the place and is an absolute mess to read.

I noticed that it was hanging up at a simple unistd sleep(1) command that
was in one of the program's many thread functions.  I noticed then when I
ran the same program on a linux box without ngpt and it worked fine.

I know this is a highly vague description but has anyone seen any problems
where a simple sleep() command would cause a hangup where normal linux
threads would not?

-Toshi.