In this case, based on what you've described, you do NOT yet have acceptance. The offer has been verbally accepted, by the seller, but in a short sale, the seller is not in charge of whether or not they will accept the offer, that is up to the bank, and you need to receive written acceptance from the bank.
Once you have written acceptance from the bank, then the local MLS rules will come into play and they will have to update according to those rules.
I am FROM Houston, but can only speak for real estate laws and MLS services in Georgia.
The seller generally doesn't have much say in accepting a short sale offer. Until the bank gives it approval it's not really under contract - unless the buyer has already reached a number with the lender and your number meets that one.
Once the lender accepts your terms, you should still be aware of the following things:
The primary determining factor in this would be if your purchase has any addendum or special language stating that the seller can continue to market the home through a certain time - especially during any contingencies.
Additionally, it takes the MLS service here a few days if not a week to update status sometimes - depending on a number of factors that are generally out of anyone's control.
The most important thing for you to check - and really the "only" thing that could adversely affect you is if the bank (in a addendum) reserves the right to negotiate other offers - even if they are under contract with you. Your best bet is to check on that first and foremost.
I hope this helps you!
In my area, Northern Virginia, many companies have started using a Short Sale Addendum, developed by the companies, not by our Board of Realtors, which includes verbage indicating that parties agree it is not ratifed until the Seller delivers to the Buyer proof of the 3rd party approval. The addendum also says that the Earnest Money Deposit is not to be deposited until 3rd party approval is received. How can the check be deposited if the contract is not ratified.
If your contract has this type of addendum, spelling out that it is not ratified until the 3rd party approval then the agent is correct not to change the status in the MLS. If though there is no addendum spelling this out, and the contract is Ratified (look on your contract for a ratification date), and your check was deposited, then the status should be changed and you agent should be making calls insisting the listing agent change the status. With my MLS if you do not change the status an agent can be fined as much as $100 for the first violation, and if they continue to leave it Active the fine will rise.
You should push the issue with your agent to get the listing agent to change the status, and if they do not get results go to their manager and have them make a call.
Best of luck
In today's market, it takes longer than ever for short sale contracts. The time frame from submitting an offer and receiving written acceptance from the lender can take months. During that time, a buyer may change his or her mind as well, and many do! It is in the seller's best interest, in this case the bank/lender, to keep the listing active until both the buyer and seller have signed the contract.