Hi
I had also some issue with code signing, but I was able to resolve them. I'm using Windows 7 Home Premium. Here's what I did to resolve my issue:
1) Check options in Advanced Installer: Options/Exernal Tools.... -> Verify that the signtool.exe is pointing to the right version of the Windows SDK.
2) Check which version you need and download the appropriate Windows SDK:
http://msdn.microsoft.com/en-us/windows/dd146047.aspx
I was using version 6.0.6000.16384.10
3) Verify that the certificate is valid. View the certificate and check that there are no issues with the certificate path. If you are not sure, verify with the vendor of the certificate that it is valid.
4) Use command prompt, change to the directory where Windows SDK is installed and run command "signtool.exe signwizard" (without quotes). Go through the steps of the wizard. Note: the latest version of Windows SDK (6.1.7600.16385) does not have a signwizard anymore. You have to pass arguments in command line mode.
5) If using timestamp URL, make sure that security or proxy settings don't block you from calling the url. You need an active internet connection to perform this task.
What I learned is that it is most likely not an issue with Advanced Installer. I assume that Advanced Installer calls the Windows SDK in command line mode passing arguments to code sign the package.
I hope this helps.
Regards,
Matthias