Regarding the log in problem, yes my domain is correct www.mysite.com/newsite

Added 11 hours later:

Hmm this isn't just a problem with symisum-03 I tried it with veronese too (#login - then a grey box appears to log in) and I just can't log in from the header.

 I will try to get help in the support forums since it is not a skin problem

One last thing, is it possible to have the Latest Comments in the funky box at the top, next to latest forum posts.

Normally this is already inside the theme.
In header.tpl, yuo will find on line 79 the following:

			<!-- If you want an extra tab between Forums and Pages. Change also header-latest_original.png in header-latest.png
			<div id="comments" class="tabcontent">
				<h4 class="none">{PHP.themelang.index.Recentcomments}</h4>
					{PLUGIN_LATESTCOMMENTS}
            </div>
			-->

Remove the <!-- and --> and do what the text say about changing the pictures.

And line 92

!-- If you want an extra tab between Forums and Pages
					<li class="c"><a href="https://www.cotonti.com/#" rel="comments"><span>{PHP.themelang.index.Recentcomments}</span></a></li>
					-->

And then you have to look for the right plugin to show the comments. It existed but I can't find it directly.

Added 1 hours later:

#35552 musashi9:

Hi, I have the latest version of Cotonti and I want to use the symisun-03 Theme, but none of the header submits work

I try and log in and it just sends me back to the same page and I am still logged out.

Are you sure your domain in config.php is right? Without the ending slash?

Hi, I have the latest version of Cotonti and I want to use the symisun-03 Theme, but none of the header submits work

I try and log in and it just sends me back to the same page and I am still logged out.

When I try to use the search box on the header It takes me to the search page but doesn't show me any results.

One last thing, is it possible to have the Latest Comments in the funky box at the top, next to latest forum posts.

Don't know about the login form in the header, it works fine for me.

Regarding the searchbox, change the following on line 125 in header.tpl:

				<input type="text" name="rsq" value="{PHP.L.Search}..." onblur="if(this.value=='') this.value='{PHP.L.Search}...';" onfocus="if(this.value=='{PHP.L.Search}...') this.value='';" class="sq" maxlength="40"/>

To:

				<input type="text" name="sq" value="{PHP.L.Search}..." onblur="if(this.value=='') this.value='{PHP.L.Search}...';" onfocus="if(this.value=='{PHP.L.Search}...') this.value='';" class="sq" maxlength="40"/>

I try and log in and it just sends me back to the same page and I am still logged out.

When I try to use the search box on the header It takes me to the search page but doesn't show me any results.

One last thing, is it possible to have the Latest Comments in the funky box at the top, next to latest forum posts.