Consider the following bidirectional text in MS Word 2010, where the caret was positioned with a mouse click right at the left of the Hebrew letter dalet.
If I then press Delete, the caret moves to its new position :
As far as I can understand the caret should not move in this case. Any explanation ?
The caret "moves" from being just after (but visually before) the dalet to just before the end of the line. These are in different visual positions but the same logical position.
I also compared the behaviour in Firefox 4 (which I happened to have handy) and Firefox 15 (Nightly). Firefox 4 has a bug where pressing right arrow cycles though the Hebrew characters, however it doesn't move the caret when you press delete in your situation. Firefox 15 does not have the right arrow bug, but it exhibits the same delete "bug".