You probably have some issues with the JobScheduler/JobEngine/Module Engine services...
Do you see some fatal errors in the below files?
C:\Documents and Settings\All Users\Application Data\SolarWinds\JobEngine\Logs\
If you need help to analyze them, feel free to open a support ticket or to post your questions here.
I trawled through the \Program Files\SolarWinds\Orion\NPM.BusinessLayer.log and there was indeed an entry about the pollers. The error stated "Input string was not in a correct format". I then changed the format to text and it is now working ok.
Thank you very much for your help!!!
5-stars self-solved issue :), thanks for sharing the solution.
I suppose it is far easier once you know where errors are logged.
I detailed further log files in this post if you're interested: Re: Identity of critical logs please
Thanks for the tip, I will take a look! :)