Problem when adding ibproarcade as a plugin

It's really weird, I have had the arcade installed before - got hacked - took it completely off - then tried to add it from scratch, used the instructions, got to the bit where you go to the admin section, Enter the path to the Product-XML-File: ./includes/xml/product-ibproarcade.xml and click IMPORT
Confirm the Import of that Product

Then it comes up with an error :

Not Acceptable
An appropriate representation of the requested resource /admincp/plugin.php could not be found on this server.

Which is weird, as I went and looked and I have a file /admincp/plugin.php

Please can someone help me

(I'm running VB 3.6.8 patch level 2 and trying to put in the latest version of ibproarcade)

Thanks

--------------- Added [DATE]1203730963[/DATE] at [TIME]1203730963[/TIME] ---------------

and... I just went now and re-uploaded plugin.php just to be certain - and it still comes up with the same error

--------------- Added [DATE]1203741710[/DATE] at [TIME]1203741710[/TIME] ---------------

Don't worry I figured it out