chieldave,

Firstly, I don't think you have any need to change your plans.
I also don't think you should have any concerns about the 'financial condition' of the May bank statement since the key really is match up the payslips with payments going into the bank account.
Under the new rules the UKBA is not concerned at all about the 'financial condition'.

The purpose is not to draw up a personal financial balance sheet for each couple (outgoings, credit card and other debts, mortgage, etc), but to take £18,600 (or the higher level for children) as a benchmark for financial stability and independence on the part of the partner or the couple.

The very important link is that between payslips and bank statements over the 6 month period immediately before the vis application.

As others have said you MUST secure a duplicate playslip from the employer or at least a covering letter from the employer with an explanation of why a duplicate cannot be provided. Such a letter would need to confirm the MAY salary details.

Please do not be tempted to miss that payslip from your submission. The caseworker will at best request it and at worst may refuse the application.

Here's what UKBA say about that situation:-

Caseworkers have discretion to rectify minor errors in an otherwise compliant application, e.g. where the applicant has made a simple arithmetical error in adding up properly evidenced figures in the application form, or where the application would meet the financial requirement except that a piece of specified evidence is missing (e.g. one bank statement in a series) and contact with the applicant establishes that this can be submitted quickly. If the applicant fails to send the specified document(s) within the requested time period, the application will fall for refusal.

Hope this helps

BTW It was me who added the highlighting in the above quote