This might not be a bug as such, but I've noticed that, when opening .INI and/or .LVL levels in the Editor, some of the objects are missing, specifically the water objects. It doesn't happen in every level though, and - wierdly - sometimes some of the water is there, but the rest of it isn't.
I'm guessing it might be something to do with how objects are named/understood between the different file formats, but I could be wrong. Is there's a way around this whilst .INI/LVL files are still supported by the Editor? If so, it would save a ton of editing...