Greek Web Masters

I have read the FAQs and checked for similar issues: YES / NO
My site’s URL (web address) is: http://bit.ly/45Ra50
Description (including timeline of any changes made):

Overview:
Our website (http://bit.ly/45Ra50) relaunched and went live in May 2010 and since then was doing very well. We are proactive when it comes to creating useful content information via guides, articles, and news, and we have added a number of services pages to cover a wide range of services in different locations across the UK. We take part in purely white hat techniques and to date have tried to stick to the Webmaster guidelines as much as possible.

Issue:
However, we have noticed on Saturday 23rd that our rankings dropped significantly in Google across all terms. Some pages dropped by 3 pages and others completely out from the first 300 pages (although still in Google index).

Ranks:
solicitors – was 7, now 11
find a solicitor – was 3, now 10

solicitors london – was 8, now 69
solicitors liverpool – was 18, now 92
solicitors manchester – was 4, now 30

accident claim – was 35, now 68
accident claims – was 31, now 155
no win no fee – was 38, now 56

no win no fee solicitors – was 22, now 48
compensation claims – was 30, now 300+
medical negligence – was 74, now 136
personal injury – was 17, now 83

What have we done wrong? Has anyone else noticed these issues?