Hibernate as post command - Agent does not report properly to Management Server

Hi!

As we are performing backups at night, we usually set the machines to hibernate mode after a backup has been performed. We do that using the command
shutdown /h
executed as a batch file (.bat) and called as a post command from the Acronis Backup plan.

Now, with a SSD in the clients and Acronis B&R 11.5 everything works so amazingly great, that the backup is succeeded and the machine is set to hibernation so fast, that the clients do not have enough time to report the result to the management server.

This leads to the following behaviour:
The "Current Activities" list on the Management Server shows a lot of running tasks that are actually already finished. This list is either updated when the machine is turned on the next day or after a while, the management server assumes that the backup has failed and drops a lot of alerts. The view in "Machines with agents" on the Mgmt server (containing infos like result and last backup date/time) is updated, as soon as the machine again contacts the Mgmt server.

So far I was struggling with the following problems:
1. the /t paramter is not allowed when using shutdown /h so I cannot delay the hibernate mode
2. calling another batch or command file having a delay (ping localhost or timeout /nobreak) does not work, because the backup is not finished until the command is executed completely
3. furthermore, the start or call statements that actually forces the next command to be executed as another process, has no positive effect on this behaviour, as Acronis also waits for this new process to be finished until it completes with Success.

Was anyone facing the same issues and knows how to deal with it? Is there any possibility to tell the client to wait going hibernate until all infos about the backup were sent to the Mgmt server?
I would like to avoid using third party tools that do this for me and use the resources I have, so I don't have to go through a complex process of granting permissions to another executable that may solve the issue (company policy, anti-virus software, etc.).

We are using B&R11.5 Adv. Workstation Built 32308 on Windows 7 clients. The Mgmt server (same version) is on a Windows 2008 R2 server.

Any help is appreciated.
Thanks & Cheers,
Tom