Sign Up form: different behaviour in pop-up dialog and on qa.jtalks.org/jcommune/user/new page

Description
Preconditions:
1. Open http://qa.jtalks.org/jcommune/user/new page in one tab
*Choose localization (will be advised if necessary)
2. Open http://qa.jtalks.org/jcommune/ page in another tab
*Choose localization (will be advised if necessary)
3. Open pop-up dialog by clicking on Sign Up link

#1 Steps to reproduce:
Password and Confirm password fields:
4. Enter 1 character and several spaces before and after the character (e.g. " a ")
5. Submit the form
6. Enter 2 characters and several spaces between the characters (e.g. "a b")
7. Submit the form
Actual result on a page:
The form drops any number of spaces entered one by one to 1 space (before/after/in the middle of a word).
(User can not register with a password containing several spaces entered one by one)
Actual result in a pop-up dialog:
The form shows all spaces entered one by one (before/after/in the middle of a word).
(User can register with a password containing several spaces entered one by one)

#2 Steps to reproduce:
4. Enter different passwords into Password/Confirm password text fields (e.g. "1" and "2")
5. Submit the form by pressing Enter key
Actual result on a page:
Entered passwords are not reset after submitting
http://screencast.com/t/WHPnbqIQVLCO
Actual result in a pop-up dialog:
Entered passwords are reset after submitting
http://screencast.com/t/JIjIWJkK9YbO

#3 Steps to reproduce:
*Choose Ukrainian localization
4. Submit the form by pressing Enter key
5. Overview the Captcha field placeholder
Actual result on a page:
Captcha field placeholder is not displayed full-length
(Maybe it's possible to use a label instead of a placeholder or increase form field's width)
http://screencast.com/t/MKe6k6wXmvdK
Actual result in a pop-up dialog:
Captcha field placeholder is displayed full-length
http://screencast.com/t/P6Yy53Ct0k

#4 Steps to reproduce:
4. Enter unregistered username and several spaces in the middle of the word in Username text field (e.g. "a b")
5. Submit the form by pressing Enter key
6. Pop-up dialog: enter valid data into other form fields
7. Pop-up dialog: submit the form
8. Open email with activation link and overview username in hellow message
Actual result on a page:
The form drops any number of spaces entered one by one in the middle of the word to 1 space.
User can not register with username containing several spaces entered one by one.
Actual result in a pop-up dialog:
The form shows all spaces entered one by one in the middle of the word.
After successful registration spaces in username are dropped to 1.
User can not register with username containing several spaces entered one by one.

#5 Steps to reproduce:
4. Type several symbols in Username text field
5. Submit the form by pressing Enter key
6. Overview the blinking cursor positioned in Username text field
Actual result on a page:
The blinking cursor is at the beginning of the typed text in Username field
Actual result in a pop-up dialog:
The blinking cursor is at the end of the typed text in Username field