Signal/Interrupt oddities

[Butler, Paul]

I have two G5's running:

YDL 3.0 - 2.6.4-1.1321smp kernel

I have an Ada program that attaches an interrupt handler to SIGUSR1 =
(this doesn't seem to matter, I've tried several different signals with =
the same result), and then sets a timer to fire that interrupt/signal.  =
It works fine on one machine, but doesn't on the other.  I can compile =
the program on either machine, and run it on the other, and the outcome =
is the same.  One machine throws/catches the signal, the other doesn't.  =


Oddly enough, I have another test program that doesn't actually attach a =
handler, but uses a POSIX wait for a timer to expire and it works on =
both machines.  So something must be up with the Attach_Handler =
processing on the one machine that doesn't work.

My question is what could I have done to the one machine to cause Linux =
to ignore signals in this manner.

Thanks.