Bank reconciliation

[David Goodenough]

I imported transactions from my bank using "import ofx" which has 
populated an account called "Imbalance-GBP" with various transactions. 

One of the transactions represents paying in three cheques we had 
received as payments for ads from three different customers which the 
bank lumped together as one transaction. 

>From googling I had come to the conclusion that I should set up a temporary holding 
account (Account type: Asset), have that transaction pay into said account and then make 
three different transactions to Assets:Checking Account and use them to pay the invoices. 
However, when I (using the right click menu option while viewing all transactions in said 
holding account) assigned these 
transactions as payments for the invoices the transaction was moved to 
Accounts Receivable automatically and moving it back (by editing the 
other end of the transaction in Assets:Checking Account) causes the 
invoices to become unpaid.

Clearly I am doing something wrong, quite possibly by not even using the 
right solution to begin with and I don't think banging my head against 
the problem/google any more will be productive, what should I do?

In short, what is the proper way to handle the case where a single paying-in transaction 
needs to be reconciled against several invoices for multiple customers?  

We try to encourage people to pay electronically, then none of this happens, and in future 
if we can not find a solution to this we will ensure that cheques are paid in individually, but 
we need to handle these historic transactions.

David