BUG: (low) split window makes Workspace unloadable

[R2-D2]

I've finally tracked down a bug that was in TextPad v4 and still there when I upgraded it to v5.0.3. If you split a window with a low horizontal split (towards the bottom of the window) then the resulting workspace cannot be loaded. I traced this by making the split in the middle of the window and saving the workspace, then moving the split down and saving as a new workspace. The latter could not be loaded, but comparing the .tws files showed one byte of difference. Altering this byte to a smaller value made the workspace loadable (and moved the split up the window).