Windows app cert kit hangs

I am trying to run the WACK tool on my windows store project but it
always ends up hanging on the step "Validating app...".
I have had it running for hours, but it never finishes.

The only way to stop the process, is to kill it.

Heres the last 3 lines in the log trace :

appcertui.exe Information: 0 : 2012-12-30 18:40:33 INFO:Executing task PerformanceLaunch.
appcertui.exe Information: 0 : 2012-12-30 18:40:33 INFO:TAEF command-line "C:\Program Files (x86)\Windows Kits\8.0\App Certification Kit\Microsoft.Windows.SoftwareLogo.Performance.dll" /select:"@Name='Microsoft.Windows.SoftwareLogo.Performance.Performance.Launch'" /enableWttLogging /logfile:"C:\Users\samaca\AppData\Local\Microsoft\AppCertKit\Log_PerformanceLaunch_VALIDATION.xml" /p:"DataFilePath=C:\Users\samaca\AppData\Local\Microsoft\AppCertKit" /p:TaskParameter=POST_PROCESS /p:PackageFullName=34570gokodogames.fruitsmemory_1.0.1.2_neutral__43s0ve21zq99m /p:"AppxManifestFilePath=C:\Program Files\WindowsApps\34570gokodogames.FruitsMemory_1.0.1.2_neutral__43s0ve21zq99m\AppxManifest.xml".
appcertui.exe Information: 0 : 2012-12-30 19:08:30 INFO:User initiated stop execution.

Any tips on how to investigate this further, or resolve the issue?

Thank you!