The subtleties of Silverlight’s cross-browser compatibility

Last week we put our first full-blown Silverlight 4 line-of-business application into production, and just yesterday, we’ve run into our first production issue. Consider the width specifications of the DataGrid columns in this XAML fragment:

This XAML file was generated by Expression Blend and has not caused any problems throughout the development phase and during user acceptance tests. However, on one particular Windows XP/IE7 system it caused a crash, even though all systems were using Silverlight 4.0.50917.0. After a bit of investigation we learned that by design a star-sized specification should include an integer and not a double. The big mystery is why this is not detected by the compiler and why it works on all other systems…