opera send mail password trough post content on third side site

This is forum site when I'm post new topic, and analyse HTTP request I'm found that in post method send my login and password from my mail.

Version information
Version
11.51
Build
1087
Platform
Win32
System
Windows XP
XHTML+Voice
Plug-in not loaded
Browser identification
Opera/9.80 (Windows NT 5.1; U; en) Presto/2.9.168 Version/11.51

Content-Type: multipart/form-data; boundary=----------Zpwkjxc81DxIByPO2BcmRi

------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="st"

0
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="act"

Post
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="s"

987834a0b81a6cbf2f5818ab9c0ce9f4
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="f"

26
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="auth_key"

02e0f2c0dabbc30edd29ec02c685b8c5
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="removeattachid"

0
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="MAX_FILE_SIZE"

2097152
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="CODE"

01
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="attach_post_key"

15fff6262db9179d54e5f48420f07633
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="TopicTitle"

íàçâàíèå òåìû
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="TopicDesc"

îïèñàíèå òåìû
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="poll_question"


------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="ed-0_wysiwyg_used"

0
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="editor_ids[]"

ed-0
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="Post"

òåëî òåìû
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="enableemo"

yes
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="enablesig"

yes
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="iconid"

0
------------Zpwkjxc81DxIByPO2BcmRi
Content-Disposition: form-data; name="dosubmit"

Ñîçäàòü òåìó
------------Zpwkjxc81DxIByPO2BcmRi--
CAPA
USER zagco
PASS labirint
CAPA
UIDL
QUIT

What is the problem? Browser? site? criticality?