Motorola

I am using distinctive ringtones for some of my family--so when they call I can tell by the ringtone who it is (can't see the display in bright sunlight). This is a very useful feature, but I find that when the same family members send me a text message it also uses the distinctive ringtone, so my problem is I cannot tell an actual voice-based call from a text message just by hearing the ringtone. I guess there is nothing I can do about this, right? If I use the stock rings I can set up a different kind of beep for a text message, but if I want distinctive ringtones for a person then that's used for everything. Why would they do something like this. Grrr. My provider is Cingular.