Checking Account Balancing

[ANTHONY NELSON]

Hi Folks,

I'm hoping you can help me resolve an issue.  

I created an invoice with two line items.
Invoice 333
     Service A: $100
     Service B: $200
  Total: $300

The customer sent me a check for Service A ($100) in July.  I deposited this into the checking account, and the $100 shows up in my bank statement.
Later in August the customer paid for Service B ($200), which I deposited. 
Then I received payment in GnuCash.

Now when I try to reconcile my July bank statement I can't because the bank statement includes a deposit of $100, but GnuCash is expecting the $300 in August.

How can I back out of this and rectify the situation?

To make matters worse, my company's year end is September 30, so I need to resolve this quickly.  Any help would be appreciated.

Thanks,
Tony