Subaccount totalling oddity

[Fred Bone]

GnuCash 2.4.11 r22268 on WinXP-Pro SP3.

I have a subaccount of "Assets" called "Reimbursable Expenses", with nine 
subaccounts of its own, where I put ... well, it should be obvious. Only 
two of the subaccounts have nonzero balances, currently at 27.90 and 8.49 
(and all txns are in the past); however, the amount shown on the 
"Accounts" tab under both "Present" and "Total" is 4.30 (I would expect 
36.39). The subaccounts show the expected values in the "Accounts" tab.

Trying to resolve the discrepancy I moved the subaccounts to a new 
parent, upon which the offending account shows -32.09. However, the 
current balance (shown when opening the account) is zero.

Running "Actions->Check & Repair" makes no difference (AFAICT).

Any suggestions on tracking down the cause?