I dont know how u have created this WinPE automation partition .
Please check whether the configuration is present BWPKgs folder present in "Program files\eXpress" folder structure.
If it is present just you need to do following steps again
1.Connect the thin client again to your DC .
2. Go to DC and check whether thin client is shown .
3. Check DC window if it is showing "Deployment console Thin client View" then Go to View and uncheck show thin client view checkbox (That will bring back you to normal view).
4.Now again check whether thin is visible in DC
5. Then Go to View --> Resources
6. Click on BWPKgs folder under which you will find the WinPE automation package that u have created using BDC
7.Select the appropriate package and drag it on thin client shown in Computers Pane
8. Now the package will be installed on your thin and the thin will be reboot
9.Once the thin is up go to properties and check "Automation Partition installed " : Yes
10.Now go to thin client view again (View--> Show thin client view)
11.Right Click on it and say Capture image.
12 .Now you are not supposed to do anything hear (Thin will boot into automation and imaged and then boot again to production ).