Hi All,
I downloaded a copy of SS 3.03, and trying to upgrade my site to this version.
I hit a few issues, which I've managed to get around, but now I'm stuck with this one, so any help will be massively appreciated!

[Strict Notice] Declaration of CommentAdmin::EditForm() should be compatible with that of LeftAndMain::EditForm()
GET /index.php/admin/pages
Line 318 in /xxxxx/xxxxx/cms/code/CommentAdmin.php

Cheers in advance

You probably need to add a parameter to your CommentAdmin::EditForm() declaration so it matches:
https://github.com/silverstripe/sapphire/blob/3.0/admin/code/LeftAndMain.php#L1003

So, adding $request=null should do it.

Comments module has probably been kept up to date in align with 3.1 so try downloading the new 3.1 beta. You should use that or 3.0.5.

Thanks both for the reply.

I've updated the files to the 3.0.5 version, but it still throws an error as it's trying to look for a file that don't exist...

[Warning] require_once(/public_html/cms/code/CommentAdmin.php): failed to open stream: No such file or directory
GET /admin/pages/edit/show/1
Line 82 in /public_html/framework/core/manifest/ClassLoader.php

Why would it be trying to look for the old file?

Trace

Trace
SS_ClassLoader::loadClass 
ClassLoader.php:82
SS_ClassLoader->loadClass(CommentAdmin) 
spl_autoload_call(CommentAdmin) 
ReflectionClass->__construct(CommentAdmin) 
CMSMenu.php:271
CMSMenu::get_cms_classes() 
AdminRootController.php:40
AdminRootController::rules() 
AdminRootController.php:83
AdminRootController->handleRequest(SS_HTTPRequest,DataModel) 
Director.php:296
Director::handleRequest(SS_HTTPRequest,Session,DataModel) 
Director.php:119
Director::direct(/admin/pages/edit/show/1,DataModel) 
main.php:126

Did you try doing a ?flush=all after updating the files?