are you part of Arachnoboards.com at all? if you have caging problems it would probably be a good idea to ask some people over there, they're very nice and many of them have HUGE arachnid collections. i've had about 50+ tarantulas over the past 4 years that i've been keeping them and i've only had one s'ling tarantula die... and a couple wildcaughts that probably died of internal parasites.
what types of T's do you have? and what are you keeping them in? i might be able to help you on here if you don't have an account on the arachnid forum