It seems acrobat 5 has sice detection code, the application will not load when sice is loaded. Is this a known behavior of adobe acrobat?

Yes, and it has also been discussed before on this board. If you would have searched for "acrobat softice", the following thread is one out of the six hits you would have gotten:

http://www.woodmann.net/forum/showthread.php?t=2477

thanks, got a little lazy there. :P
I actually looked through google but couldn't find a useful link.