The time it takes is very dependant on a number of factors. The severity of the injury, how long it has taken to make a full recovery, has a full recovery taken place, and has liability been disputed by the other side?
A minor injury will/should settle in around 12 to 18 months, a more sever injury could take up to 3 years, and the more severe injuries such as a brain injury could take anythinng in excess of 4 years.
The fact that your accident occured in 2007 and you have been unable to return to work suggests that your injury was quite severe, and will take longer ti settlle as the issue of quantum cannot be determined until such time as an independent nmedical expert has examined you and made a prognosis.
It is not uncommon for the third party insurers to drag their heels in cases like this, but what is important is that given that your accident occured in September 2007, proceedings must be issued by September 2010, otherwise your claim will become time barred.
You really need to get hold of your solicitor and find out what is happening given your statute of limitation.
Once proceedings have been issued, there is no hurry as you are protected, and it often gets the other side focused as they know they are liable for additional and substantial costs, but the issue is time limitation and the three year rule, you do not have much time to be protected.
I work in personal injury law, and so if you have a query or would like to discuss your situation in total confidence and without obligation, then I will be delighted to assist.