IMO you are going to keep having problems. The wheel wasn't properly tensioned (nothing wrong with Sapim spokes btw) and the constant flexing of the spokes has left them weakened. Most cost effective (and best IMO) way to solve the issue would likely be to replace all the spokes as they are probably going to keep breaking. This assumes that the rime and hub are still in good working order. Replacing the rear wheel will solve the issue at least temporarily but with factory built wheels it'll likely come back.
Edit: as I'm sure someone is going to mention it, I don't think 288 is too heavy for a properly built 28 spoke wheel. Sure more may be stronger but IMO you don NEED to go buy a 36 or 40 spoke wheel. Especially if that is a downward moving number.
Last edited by wfournier; 08-07-12 at 09:18 AM.