Also occurs on Firefox 22, Windows & Linux & OSX.

Cant reproduce on Chrome.

I've tested a few times, and I am not seeing a 'page down' effect now.

However using the arrow keys anywhere near references in VE cause the arrow keys to start misbehaving.

Steps to reproduce:

1. Load https://en.wikipedia.org/wiki/Jos%C3%A9_Cl%C3%A1udio_Ribeiro_da_Silva?veaction=edit which will place cursor at the beginning of the first line of text.
2. Press the right arrow until it moves past the reference at the end of the first paragraph, into the second paragraph.
3. Press up arrow

Result: The cursor disappears

Steps to reproduce:

1. Load https://en.wikipedia.org/wiki/Jos%C3%A9_Cl%C3%A1udio_Ribeiro_da_Silva?veaction=edit which will place cursor at the beginning of the first line of text.
2. Press right arrow (or use mouse) to place cursor further right on the first paragraph relative to the position of the first reference in the first paragraph.
3. Press down. (the cursor should now be directly right of of the first reference)
4. Press down.

Result: The cursor is stuck on the first reference.

(The same result can be achieved by placing the cursor in the second paragraph and pressing up)

I believe that it's now fixed, yes. The cursor getting stuck on down is odd and I'll make a new bug for that.

(In reply to James Forrester from comment #3)

I believe that it's now fixed, yes. The cursor getting stuck on down is odd
and I'll make a new bug for that.

Now in bug 64983.