Joomla site extremely slow

[Stingraynut]

I'm still struggling with this problem, with sadly no solution. I am slowly clearing a tangle where the DNS pointed to JustHost who had redirect to USWDH - there the account was a .biz domain name and should be .com.au so on that account there was a redirect from .biz to .com.au

When I fixed that the TTFB showed only 3.6 second but this morning it was back to 10secs then later 3.6secs and then 12 seconds !!

The host, USWDH,tested by transferring the complete site to a known good server and there was no significant speed change. They have been extremely helpful.

I can see lots of delays after ttfb, the scripts need to be combined or shrunk, some large images etc - and I can handle that- but what the heck happens in the currently 9 second gap after dns lookup (1 second!!!!) and initial connection? Here's a recent speed test - http://www.webpagetest.org/result/111209...1/details/

Surely there is a scanner or program that can tell me what is going on in that time? It must be a black art because even the host don't know what is happening there.