If you want to enter Beginning Balance type entries, they need to be dated in the prior fiscal year.  In your case, since you will have a short year, you need to "fake it out".  If you want your beginning balances to be 4/30/03 and you will then have activity 5/1 through 12/31 for your short year, then set the fiscal year start date to 5/1/03 so the beginning balances are considered to be a prior period.  Or, enter them as a Type 1 General Journal rather than Type 5 Beginning Balance.