If you're still stuck do a full debug log and i will try puzzle it out. You could look in myweather.xml so see if there even IS a control 50 (assuming 12600 is the window ID - not at home right now!)
Addons I wrote &/or maintain:
OzWeather (Australian BOM weather) | Check Previous Episode | Playback Resumer | Unpause Jumpback | XSqueezeDisplay | (Legacy - XSqueeze & XZen)
Sorry, no help w/out a *full debug log*.