Previous (non-nursing) job - let go for "unsatisfactory perfomance". Still hireable?

Last year I worked for a company that let me go for "'unsatisfactory performance". I disputed this allegation, but it's still in my record. Now I am being offered a job in a sub-acute facility and they will do an Investigative Consumer Report, and will most likely find this statement in my record. Will this record prevent me from being hired necessarily? I have seen that a lot of nurses are let go for "poor performance" from hospitals. Do these nurses get hired again by hospitals? Does anyone know if there is anything I can do to increase my chances of retaining this position despite this negative mark in my past employment record?

Also, in my application, can I say that the reason for leaving this aforementioned company was "not a good fit", and will that satisfy the truthfullness of my statement? I don't want to be accused of falsifying my application.

Thank you for any insight you may have. I am really upset about this, as it is the first nursing job in a medical facility that I have been able to obtain after graduating 2 1/2 years ago. I have been working in home care for 4 months with a very good record and I have excellent professional references.
I guess the best way is telling the truth. I believe people do give you the second chance since you have accomplished your school with a home care experience, they should look at the whole picture. Best luck to you.
12/12I hired one of those internet companies to do a background check on the employer that I left 'cause it was better than they terminating me, and when they contacted the employer, the HR technician only disclosed, via fax, my dates of employment, job title, and pay level, other questions such as: elegibility for re-hire, how was this individuals work habits, getting along with co-workers, etc they answered as "unable to disclose information per company policy" I paid about 50.00 for the report and it gave me great relief. Try it and good luck on your job search.