Cobra preexisting conditions

I was employed for twenty years in Pa. and had the same medical insurance for all those years. In the last year of my employment the company decided to change carriers. I was insured with the new insurance company for the last 9 months of my employment. When I was terminated due to my position being done away with I was offered cobra which I immediately took. There was never a lapse in coverage. After paying for my cobra for 11 months the company changed carries once again back to our original carrier but to a ppo plan as opposed to the regular plan they had in the past.  Now here is the problem.  I can’t believe what I am being told. It seems now that when my Cobra runs out in 3 months and I need to buy insurance on my own that all pre existent conditions will be uninsurable or require a rediculous premium (alreday $900.00/month) because I have not been with the current plan for 1 year.  This is incredible because I was with this company for over twenty years and I have never had a lapse in insurance. Although because of a decision made by my employer I did have a different company for one year. Can this be?