A 6th stake of identical size came through, and this negative stake has actually removed coins from my account!
Status: 1/unconfirmed, broadcast through 3 nodes
Date: 8/20/2014 02:27
Debit: 0.00 MMXIV
Net amount: -0.126327 MMXIV
Transaction ID: 212bbf60e7f3e2e6e8564eb93249edecf937086a4749b3d3877ba5803a5991d9
That is normal for it to show a negative amount. Since it is removing those coins from 'Balance' and putting them into 'Stake'. Then when the coins come out of stake that message is updated with the amount of coins that were stakes. I looked and 9 different wallet that I have staking and I see that with them all. Here is an example of APEX.
Status: 36 confirmations
Date: 8/19/2014 15:00
Source: Generated
Debit: 0.00 APEX
Net amount: -1199.2167945 APEX
Transaction ID: 4387da59643aefc6bdda8ed7356ed12eb928209f678074d9c341974036619e25
Status: 445 confirmations
Date: 8/19/2014 15:00
Source: Generated
Credit: 1.74405502 APEX
Net amount: +1.74405502 APEX
Transaction ID: 4387da59643aefc6bdda8ed7356ed12eb928209f678074d9c341974036619e25
While the coins are being confirmed it will show the amount of coins that were put into stake that is why a negative number. Then once the come out of stake that amount will show the amount of coins that were staked. So there is nothing wrong with the wallet trying to create a negative coins when staking.