Hello and welcome aboard.
Check these threads out, they might be a great help:
http://www.subsim.com/radioroom/showthread.php?t=180044
http://www.subsim.com/radioroom/show...18#post1854918
I'm speaking for myself here, other skippers will recommend you something different (and maybe even more useful), but this is the most stable SH modification I've had so far. Enjoy and good hunting.