It's a truism that applications have to be retested on every new operating system. We expect that. On the other hand, we've come to expect that the .NET Framework will buffer applications for operating system differences. We've been spoiled, I'm afraid, and it's not something we can count on. Take the recently released Ruby in Steel, a Ruby programming environment for Microsoft Visual Studio 2005. The first rele It’s a truism that applications have to be retested on every new operating system. We expect that.On the other hand, we’ve come to expect that the .NET Framework will buffer applications for operating system differences. We’ve been spoiled, I’m afraid, and it’s not something we can count on.Take the recently released Ruby in Steel, a Ruby programming environment for Microsoft Visual Studio 2005. The first release build was specifically supported only on Windows XP and not Windows Vista, which was a clue for me that there might be known issues, but naturally people tried it on Windows Vista anyway, and did encounter problems. I was surprised by the resolution of this particular problem: it turns out that the .NET function Encoding.UTF8.GetBytes returns a different array of bytes under Vista than XP. Who would have “thunk” it? Software Development