problems with execv and spawnv in QNX6

I am running into problems with the execv() and spawnv() functions in QNX6.
There are times when the execv() and spawnv() functions never execute the
new program or return an error, it just hangs forever. After this happens
the calling process still shows up when you do a “ps -a” along with a
process that has no name, some sort of zombie and cannot be killed with any
signal including a kill -9 without rebooting the machine. If I do a
“ps -ef” the program shows up an infinite (sic) amount of times in the
listing and never stops scrolling. If I do a “ps -ef | grep filename” the ps
hangs and never returns.

I noticed that if I touch the executable file without recompiling the code
and try to run it again everything seems to work fine, sometimes.

This exact code has been running under QNX4.25 without issue in the field
for 2 years but is very inconsistent at best under QNX6.

If anyone has experienced anything similar or knows what could be causing
this I would appreciate your input.