偶尔汉字显示异常，部分重叠

[GoogleCodeExporter]

What steps will reproduce the problem?
1. 进入MITBBS Seattle版，打开第23835篇文章"Re: 求有登顶mt. 
rainier的朋友交流经验"
此文章的web版链接是 http://mitbbs.com/article1/Seattle/32452507_3_0.html
2. 打开文章后，按2次p，到达这篇文章：
http://mitbbs.com/article1/Seattle/32452521_3_0.html

What is the expected output? What do you see instead?
Expected: 文章显示正常。
Actual: 文章中出现重叠汉字现象，见附图。

What version of the product are you using? On what operating system?
Version 2.64 release (825)

Please provide any additional information below.
此问题经常出现，但未能找到一个有效repro。

例如，如果直接打开 
http://mitbbs.com/article1/Seattle/32452521_3_0.html，则问题无法复现。

经反复尝试，只有先打开
http://mitbbs.com/article1/Seattle/32452507_3_0.html
再打开
http://mitbbs.com/article1/Seattle/32452515_3_0.html
最后打开
http://mitbbs.com/article1/Seattle/32452521_3_0.html
才会在正文最后一行出现异常显示。

Original issue reported on code.google.com by [email protected] on 13 May 2012 at 2:05

Attachments:

• [Screen shot 2012-05-13 at 9.57.47 AM.png](https://storage.googleapis.com/google-code-attachments/welly/issue-64/comment-0/Screen shot 2012-05-13 at 9.57.47 AM.png)