i think its uncommon to be refused and if it is its sually because that person IS NOT insolvent, when we went to court the clerk said she had only ever seen one refussal is 25 years !
The most common reason for a debtors petition to be refused is if that person was in an IVA and couldn't present the court with a certificate of failure/letter from their IP confirming the IVA has failed.
Julian Donnelly Spokesperson for www.Bankruptcyhelp.org.uk Don't forget the helpline on 0800 078 9367