I’m doing nothing just only upgrade to 5.1.1

and all the option button looks double again

You will see a double ‘checkbox’ if there is more than one instance of the button ID/name on the same page. So – do you have another login form being displayed on the forum page? Maybe from a widget or another plugin? If so – that can do it.

Yellow Swordfish said
OK let’s try this.
In the root simple-press folder is a file called sp-config.php

Can you make a small change in there,
Find the line that reads:

define(‘SF_USE_PRETTY_CBOX’, true);

and change the word true to the word false.

Does that help?

Hi Yellow Swordfish

I’m not sure what you meant

but i’m doing the same way u suggest before and it help solve the problem (but look a bit uglier)

I am not sure of any other way of saying it. Does your forum page have a second login form on it somewhere – like in a sidebar for example?

Yellow Swordfish said

I am not sure of any other way of saying it. Does your forum page have a second login form on it somewhere – like in a sidebar for example?

Yes, I have sidebar login plugin

As I suspected. For techincal reasons we have to use the same id’s for the forum’s in-line login form as any other wp login form that may be used. When you have two identical id’s this will, sadly, give the double ‘check-box’ graphic. We can neither change or help that I am afraid.
So I would suggest that the best way would be for you to remove the forum’s in-line logion form from the spHead theme template.