[orca-list] strange behaviour when using down arrow in a page

[José Vilmar Estácio de Souza <vilmar informal com br>]

Hi all.
Probably this is not a bug but I decided to report in the list.

To reproduce try the following steps:
1. Launch firefox and go to 
http://stackoverflow.com/questions/238002/replace-line-breaks-in-a-string-c-sharp.
2. After the page is loaded press alt+shift+k, choose the link 'show 2 
more comments' and press the enter key.

3. Press down arrow many times.
In my environment orca reads nothing.
If I press the down arrow about 100 times, orca reads the continuation 
of the page and if I press up arrow about 100 times, orca reads the link 
'show 2 more comments'.

It seems that there are 100 blank lines between the two parts of text.
Is it possible?
The problem happens with orca from master and orca 3.16.2.
Thanks.

--
José Vilmar Estácio de Souza