I'm sorry I don't have any advice except to say it's nothing to do with the PDB. If you are left "waiting for a connection" it means that the service did not run any managed .NET code. If the service had failed to start, ANTS Profiler would have left an error message, so I assume that the service had started and is running.
You can tell if the .NET runtime had loaded by examining the process to see if it loads mscorlib.dll. If this dll is not loaded by your service, you are not running managed code, and consequently the ANTS Profiler COM dll does not load into your system 9RedGate.Profiler.Core2.dll).
The other possibility is that the Core2 dll couldn't load or had crashed. In the former case, an application event log error entry saying "couldn't coCreate Profiler" would appear.