Unable to Insert Images into Pages or Posts

Hi All and thanks in advance for any help you might be able to provide…

I’ve searched through the forum and was unable to find exactly my problem although there seems to be issues uploading or accessing images with ‘WP 3.3’.

I’m unable to insert images into pages or posts. When I click on the ‘Upload/Insert’ icon it brings up an overlay screen like in ‘LightBox Plus’, (even with the ‘Blue Default Theme’, ‘NextGen’ deactivated and LightBox Plus uninstalled) sometimes there is a ‘Loading’ image, which disappears and then nothing more happens.

I say ‘LightBox Plus’ because I changed the setting from 80% opacity to 95% Black #000000 and the overlay screen appears darkened – even when I had uninstalled ‘LightBox Plus’!

Using ‘Firebug’ I get…
‘window.getComputedStyle(o, null) is null’
‘[Break On This Error] (function(){var f=0,k=[],m={},i={},a={…;g.runtimes={};window.plupload=g})();’
Line 9 load-scripts.php?

I’m no expert so I hope I’ve given that info correctly 🙂

I’ve reverted to the ‘Twenty Eleven’ theme and have tested with ‘Blue Default Theme’, I’ve reset ‘NextGen Gallery’, I’ve deactivated all my plugins, I even deleted and reinstalled ‘LightBox Plus’.
I’ve checked ‘JQuery’ in my browser through – http://digitaldoit.com/wp-admin/load-scripts.php?load=jquery. and there’s loads of code to be seen.
I’ve uploaded the entire folder wp-admin from a downloaded WP 3.3, overwriting the directory on the server.

The problem persists on both ‘Default Theme’ and ‘Twenty Eleven’ with all plugins deactivated!

My site is on an ‘Apache’ server with ‘PHP version 5.2.17’ ‘SQL version 5.1.49’

I’ve checked the problem in Firefox 8.0 and Chrome with the same result.

When responding, please remember I’m no expert and don’t understand php, jquery or ajax but would appreciate any assistance you can give me.

Many thanks in advance
SecretGarden