Since you have that problem, I assume you are playing with the stock game. Bear in ming that this and 100s other fixes are included in the Grey Wolves modpack.
Back in your case; Long ago, I made a fix for the IXD/2 similar torpedo problems. You might want to check this fix:
http://users.forthnet.gr/ath/helsing...edo_Fix_v4.zip
Check also the thread:
http://www.subsim.com/radioroom/showthread.php?t=89466
and read the readme carefully, especially if you have other mods installed.
Von