Joomla Install Session Save Path error

[#1]

I have got several Joomla websites running (three in the same PAYH space but for reasons beyond my comprehension I cannot get a new one to install. I can get the install package to open and select the language but on clicking "next" I get this error.

Quote

An error has occurred.: Cookies do not appear to be enabled on your browser client. You will not be able to install the application with this feature disabled. Alternatively, there could also be a problem with the server's session.save_path. If this is the case, please consult your hosting provider if you don't know how to check or fix this yourself.

Any clues out there it is driving me nuts now 
BTW Cookies are enabled.

[#2]

I wonder if the problem is /var/lib/php5 is full? That seems to be session.save_path on PAYH.

[#3]

Ok so I just had the same problem - I messed up my Joomla test site which was working last week - have repeated the installation process and get this same error message.

Quote

Cookies do not appear to be enabled on your browser client. You will not be able to install the application with this feature disabled. Alternatively, there could also be a problem with the server's session.save_path. If this is the case, please consult your hosting provider if you don't know how to check or fix this yourself.

Hope you can help me sort this.

[#4]

There are suggestions in this (external link) thread that Plesk might not get on too well with this package.
Also have you tried using a different browser (specifically Firefox)?