i.e. they are to loose. A properly tension built wheel will almost NEVER have a broken spoke.
Now you may have bad spokes, but if the spokes are stainless steel I doubt it is the Spokes (Regular Steel Spokes do rust and break, but Stainless steel Spokes rarely if ever break). A few years ago I used a wheel the spokes broke on me, the problem was it was built with regular steel spokes and such spokes are NOT built to the level of Stainless Steel Spokes used on better bikes.
If the spokes are stainless steel the next thing I would look at is how the wheel was built. Did the person who build the wheel do a proper adjustment? i.e. actually tighten the spokes.
I have looked at Titanium but with Titanium you must used brass nibbles, and with brass nibbles you loose whatever advantages you have with going Titanium. With Stainless Steel you can go with Aluminum nibbles, thus Stainless steel is the best choice for Spokes (For more see Sheldon Brown for details on material, this is a very brief statement on a very complex topic).
Here is Sheldon Brown's Article on Wheel Building which goes into more details than the above on Wheels and spokes.
http://www.sheldonbrown.com/wheelbuild.html