User Registration not working again

Hi everybody, I got into trouble with user registration on surveysimply.com . After you create a new account and press Register, homepage is displayed, no user account is created (in back-end) and I don't receive any email.

I'm using JOOMLA Version 1.6.2 and Hikashop 1.5

Thank you for any help!

Plugins:



Authentication - Joomla
Authentication - GMail
Authentication - LDAP
Content - Load Modules
Content - Joomla
Content - Email Cloaking
Content - Code Highlighter (GeSHi)
Content - Pagebreak
Content - Page Navigation
Content - Vote
Editor - CodeMirror
Editor - None
Editor - TinyMCE
Button - Article
Button - Image
Button - Pagebreak
Button - Readmore
Extension - Joomla
HikaShop order history plugin
HikaShop joomla user account link plugin
HikaShop trigger for AcyMailing filters
Hikashop Products Cron Update Plugin
Hikashop Orders Automatic Cancel Plugin
HikaShop AlertPay payment plugin
HikaShop Authorize.net payment plugin
HikaShop bank transfer payment plugin
HikaShop Bluepaid payment plugin
HikaShop check payment plugin
HikaShop collect on delivery payment plugin
HikaShop credit card payment plugin
HikaShop ePay payment plugin
HikaShop eWAY payment plugin
HikaShop Moneybookers payment plugin
HikaShop Paypal payment plugin
HikaShop Western Union payment plugin
Hikashop AlphaUserPoints Plugin
HikaShop SIPS Atos payment plugin
HikaShop HSBC payment plugin
HikaShop Australia Post shipping plugin
HikaShop manual shipping plugin
Search - Categories
Search - Contacts
Search - Content
Search - Newsfeeds
Search - Weblinks
HikaShop categories search plugin
HikaShop products search plugin
HikaShop user synchronization plugin
System - Language Filter
System - P3P Policy
System - Logout
System - Debug
System - Log
System - Redirect
System - Remember Me
System - SEF
System - Cache
User - Profile
HikaShop user synchronization plugin
User - Contact Creator
User - Joomla!


Modules:
Articles Categories
Articles Category
Latest News
Articles Most Read
Bottom Left Column (Atomic Template)
Bottom Middle Column (Atomic Template)
Search (Atomic Template)
Sidebar (Atomic Template)
Login (Atomic Template)
Top Menu (Atomic Template)
Top Quote (Atomic Template)
Banners
Breadcrumbs
Custom HTML
Feed Display
Footer
Language Switcher
Associated products listing for category listing menu 445
Associated products listing for category listing menu 512
Associated products listing for category listing menu 483
Login
Menu
News Flash: Random
News Flash: Latest
Search
Top
Language Switcher
Banners
HikaShop Currency Switcher Module
Tools
Purchase
User Menu
Purchase
Your cart
Login Form
Random Image
Articles Related Items
Search
Site Map
Statistics
Syndicate Feeds
Users Latest
Weblinks
Who's Online
Wrapper

Thank you! It works! But can I get back the CSS buttons?

I have got the same problem with the CSS button, using 1.66 and 1.53 business and it was solved the same way (changing to "normal").... but I did not do any changes on the javascript or the CSS on the core testing beez template regarding this topic right now. So I am just wondering where the problem is located.