Strange situation happened, not sure if its happened to any of you before.

I used my SPG Amex to book an upcoming flight here's what happened:

For the sake of things lets say I have a 100 dollar credit line (lol I dont really), and lets say the ticket was 25dollars.

I booked the ticket using my SPG Amex, so the next day I check my online activity, it shows the flight purchase (and usually you know how they have the [+][-] drop down box/menu to show extra data on the purchase? Well that was missing, but it did reflect the 25dollar transation, and my available credit was now $75.00.
Sounds good enough right?

A day later I check online and my available credit is now only $50.00! and I have made no purchases other than the plane ticket, I go to check recent transactions and now my purchase shows/has the [+][-] drop down menu showing my all my flight information. The only conclusion I can make is that when they added my flight info after they had already posted the purchase transaction, somehow the system screwed up (or somthing did) and it reduced my available credit -$25 again, even though I didn't make another $25 purchase (it did not charge me another 25 incase you were wondering, it just reduced available credit). I found this really strange, and wondering if anyone else see this before?

I'm giving AMEX a call, lets see what happened.