NEED EXPERT FOR OPTIMISE SQL . UPGRADE 1.5 TO 1.5.2.1 SLOW

Hi

IF somebody can help and contact me for this job, it will be really appreciate. I have an issue with my first byte since I did the update from 1.5.1 to 1.5.2.

Our website www.dzignart.com was before yesterday on opencart 1.5.1
The First Byte from webpagetest was at 0.6sec and the total 3.3sec

Since I did the update from opencart 1.5.1 to 1.5.2.1 my first byte is 1.5sec, so very very long.
http://www.webpagetest.org/result/120504_HV_47J42/

We have change nothing since yesterday and
-our database is still with the same number of products (2500 products),
-I have just 4 vqmod that load,
- use default theme with color modificaiton
delete count of product per category
delete log error
our apache server is setup with deflate module (gzip compression : txt, image...)

Do you have any idea of what i need to change. Database optimisation, Cache????...

Upgrade from 1.5.1 to 1.5.2.1 should increase my speed, not become very slow. I am sure that it s not my hosting, because we have full dedicated servers and everything was fine yesterday morning. Also I have subdomain on the same server, but on 1.5.1 and my first bite is 0.540

Thanks in advance

An

If your willing to invest a bit have a look at these extensions, they will help a lot.
http://www.opencart.com/index.php?route ... on_id=6204
http://www.opencart.com/index.php?route ... on_id=3477

As for optimization of your SQL, I have an analyzer / demo I could put on your site I suppose. If you want to get in touch my skype is hunter.bm

Hello Tcalp
Thank you for the reply
Yes we have a budget. I will check your link and contact you via skype
Tks
An

Find my solution in 5minutes with this module
http://www.opencart.com/index.php?route ... alp&page=1
SERIOUSLY, THE BEST MODULE THAT YOU CAN BUY. IT S A NO BRAINER
First byte before of 2.8sec, after 0.38 and a google page speed of 97.
Load Time before, 7.565s after 3.266s

Installation of the module, really simple : take 5 minutes...
you can compare
http://www.webpagetest.org/result/120505_F7_47SMB/
http://www.webpagetest.org/result/120506_WR_483AV/

Tks Tcalp