Error in the voting mechanism

An error has just occurred when voting on the comment www.habrahabr.ru/blog/good_link/4414.html#comment37205

I pressed the green button, and the comment added a ball -1 !!!

browser Flock 0.7.9.1 (based on Firefox), firebug 1.0.
Here is the firebug's log:
')
POST www.habrahabr.ru/ajax/comment_balls.html?commentID=37205&vote=up ... (1188ms) prototype.js (line 651)
ParamsHeadersPostResponse
Response Headers
Request Headers

<table border = 0 cellspacing = 0 cellpadding = 6>

<td nowrap> <span class = "comments_rating_red"> - 2 </ span> </ td>

<td style = "border: 1px solid # e1e1e1" nowrap>

<img src = " www.habrahabr.ru/i/habr_down_off.gif " border = "0" alt = "bad comment" title

= "Bad comment" style = "margin-right: 4px;">

<img src = " www.habrahabr.ru/i/habr_up_off.gif " border = "0" alt = "good comment" title

= "Good comment">

</ td>

</ table>