Old outdated plugins?

Can you enable error logging and paste some logs here?

After I posted this things were running pretty smoothly (mostly) but now the prob is back in full force.
Yesterday I could not access the website intermittently but today it only loads blank pages...
Google Analytics is telling me that my visitor numbers have dropped off from well over to 200 3 days ago to 120 yesterday and 35 today.
I tried to enable debugging 'PWD' but that does not load either.
Any suggestions on how to proceed??

Can you PM me your blog URL, admin and FTP passwords?

I disabled "Widget cache", this feature never worked for me and only caused various errors. At least debug mode is working on your server now.

I also increased PHP memory limit from 32 to 128Mb which should fix blank page errors.

- You are using several outdated plugins that may cause errors in b2evo 4.
- You should also edit (or better delete) the files _item_comment_form.inc.php and _html_header.inc.php from your skin because they were initially copied from b2evo v2 and are missing some important code.
- When you upgrade next time, don't save old files from previous b2evo version. Just rename "inc" to e.g. "inc_old" and upload the whole directory again, do this for other folders too.

Didn't notice anything unusual in your system, it should work fine.

Thanks Sam, you've been a great help!
The site is running as it used to.