Switching between apps launched through RemoteApp from Windows 2008 R2 server

I have a problem with RemoteApp on Windows 2008 R2 Standard SP1.

When I try to switch between apps, launched from RD Web Access web-page, it is not always succeded. Instead of it the target app blinks and I still remain at the previous app. In another words, the next app window remains behind the previous app window and I have to minimize the previous app before switching to the next app.

Following the recommendations given by the TechNet Online Chat assistant, I've been installed all the available updates on that server from the Microsoft Update, but it didn't help us.

Is there any way to resolve this trouble?

Thank you.