I have noticed that when I open a new application (one that is not currently running in the background) using the ctrl + enter shortcut, the window that is opened is not opened as the active window. Instead I must either click on the window with the mouse cursor or alt + tab until the window becomes active.
This is only a problem using the ctrl + enter shortcut and when there is no other instance of the application already running. If I double click the sliderdock icon or another instance is running the new window opens as the active window, and I can immediately begin typing in it.
I have not done an exhaustive test of different applications. However, this occurs when trying to open Google Chrome, SSH, and MSword. Applications such as the cmd prompt and internet explorer are not affected by this as windows preloads them at startup.
I hope if explained the issue properly and that this helps. I'm really enjoying the dock, you have done a great job with it.