Administration error - (History of uses - Coupons)

I've encountered with a problem.
I've used a pair of coupons, testing my brand new AWO Coupon PRO (updated from a free installed version) and everything's ok but entering in Administration->History of uses - Coupons,
the system doesn't list anything and prints an error:




and a bit below in the same page..



Some idea of what the problem is?

Thanks

P.S. I've Examined mysql table jos_awocoupon_user_uses and it's like this (4ur help):

Hmm, I cannot tell what is causing the problem. Can you turn on debug mode in admin->site->global configuration->systems tab. Once that is done, refresh the history of uses page. It should tell you exactly what the error is in mysql.

500 - An error has occurred.

JDatabaseMySQL::query: 1267 - Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '=' SQL=SELECT c.id,c.coupon_code,c.num_of_uses,c.coupon_value_type,c.coupon_value, c.min_value,c.discount_type,c.function_type,c.startdate,c.expiration,c.published, uu.coupon_id,uu.coupon_entered_id,c2.coupon_code as coupon_entered_code, uu.id as use_id,uv.user_id,uv.first_name,uv.last_name,uu.user_id,u.username, (uu.coupon_discount+uu.shipping_discount) AS discount,uu.order_number,uu.productids,uu.timestamp,ov.order_id,ov.cdate FROM jos_awocoupon_user_uses uu JOIN jos_awocoupon c ON c.id=uu.coupon_id LEFT JOIN jos_awocoupon c2 ON c2.id=uu.coupon_entered_id JOIN jos_vm_user_info uv ON uv.user_id=uu.user_id AND uv.address_type="BT" LEFT JOIN jos_users u ON u.id=uu.user_id LEFT JOIN jos_vm_orders ov ON ov.order_number=uu.order_number ORDER BY c.coupon_code LIMIT 0, 20

Call stack
# Function Location
1 JAdministrator->dispatch() /home/gadepe/public_html/administrator/index.php:67
2 JComponentHelper->renderComponent() /home/gadepe/public_html/administrator/includes/application.php:136
3 require_once() /home/gadepe/public_html/libraries/joomla/application/component/helper.php:162
4 JController->execute() /home/gadepe/public_html/administrator/components/com_awocoupon/admin.awocoupon.php:29
5 JController->display() /home/gadepe/public_html/libraries/joomla/application/component/controller.php:236
6 AwoCouponViewUsersHistory->display() /home/gadepe/public_html/libraries/joomla/application/component/controller.php:310
7 JView->get() /home/gadepe/public_html/administrator/components/com_awocoupon/views/usershistory/view.html.php:48
8 AwoCouponModelUsersHistory->getData() /home/gadepe/public_html/libraries/joomla/application/component/view.php:364
9 JModel->_getList() /home/gadepe/public_html/administrator/components/com_awocoupon/models/usershistory.php:57
10 JDatabaseMySQLi->loadObjectList() /home/gadepe/public_html/libraries/joomla/application/component/model.php:284
11 JDatabaseMySQLi->query() /home/gadepe/public_html/libraries/joomla/database/database/mysqli.php:474
12 JError->raiseError() /home/gadepe/public_html/libraries/joomla/database/database/mysqli.php:247
13 JError->raise() /home/gadepe/public_html/libraries/joomla/error/error.php:171
14 JException->__construct() /home/gadepe/public_html/libraries/joomla/error/error.php:136

Yes, I have seen that error before, it has to do with the character set of the tables not being compatible. Ok, in phpmyadmin, take a look at these tables specifically:

jos_awocoupon_user_uses
jos_awocoupon
jos_vm_user_info

One or more of the character sets is off. utf8_general_ci and utf8_unicode_ci do not mix it seems. You would probably have to change both the column (collation) and the table charset. To modify the table look under operations tab.

I've changed the collation for the awo tables:
jos_awocoupon_user_uses
jos_awocoupon

to utf8_general_ci
in order to be as the jos_vm_user_info table
and I still have the same problem.

I've also deleted the 2 entrances I had in the jos_awocoupon_user_uses table, but the error persists...
Any idea?
Thanx

did you change the collation of the individual columns also?

No, I didn't chage the individual columns collation.

Really I have undone all changes and applied only 2 for the "jos_awocoupon_user_uses" table:

1.Changed column "order_number" collation from utf8_unicode_ci to utf8_general_ci
2.Changed general collation from utf8_unicode_ci to utf8_general_ci (table's collation)

In administration, it lists correctly the History of used Coupons ;-)

Let's hope it doesn't fail when Gift will be done...

Thanx 4all