Can we apply for Tier 1 visa before the expiry of old HSMP?

[cottongear]

I had got HSMP visa in April 2008 which is for 2 years valid between 9-apr-08 to 9-apr-10. But, I could not travel because of some personal reasons and I wont be able to travel till feb 2010. In this case I will not be able to make use of my existing visa and I will have to apply for Tier 1 Visa by end of 2009 (that is before the expiry of my existng HSMP Visa).

My question now is : can we apply for Tier 1 visa before my expiry of my existing old HSMP visa ? I have explained my situation above, does anyone have better suggestions ?
If I can apply, I should be applying now(10 months before the expiry of my HSMP visa) as I have maintained funds and also there is possibility of further salary cuts/lay-offs affecting my qualification for visa based on earnings !

Thanks,
CG