Credit checks and all that!!!

[longtalldee]

Dear Landlords,
I have a few questions and queries which I hope you can help me with.
I am a single, professional lady in full time (well paid) employment who is struggling to find letting agents that will accept me as a tenant. In the area I want to rent it is very difficult to find private landlords and most properties available are through letting agents. My problem is this :- several years ago I was made bankrupt (through no real fault of my own, just a business venture that went bad). I was discharged almost 2 years ago but obviously my credit score/history is still very bad. All the letting agencies that I have approached have insisted that I pay approximately £150 application fee (to do credit checks & paperwork) but that this is not refundable should the credit check come back negative/poor. I have told them about my situation and that "most definitely" it will come back poor, to which they said that it was unlikely they would be able to rent to me and I would lose the application fee. So my query is this:- am I to fork out application fees with no chance of me being able to obtain a property? Is it not obvious that because I have been made bankrupt I have no credit cards, debts, store cards, loans or credit of any kind whatsoever. Therefore, out of my salary, all I have commitments to is rent and bills, so the landlord is guaranteed that I will pay.
I've been renting now for almost five years and even in the darkest hours of my bankruptcy , I have still paid my rent in full and always on time. I have basically rented 3 house in the last 5 years all of which I have improved during my stay (landscaped gardens, redecorated, put in new flooring) so that the house resembled show homes by the time I left.
Why Oh why do you landlords insist on a tenant being squeeky clean?
Is there any advise you can give me as to how I find a suitable landlord or letting agents that will take me "warts and all".
Any advice would be appreciated.