From the sounds of it the logs are pushed/deleted off of the MWG by the time Web Reporter can get to them. MWG will only delete log files according to your log file deletion settings (which are set under Reporting > Log File Management > Auto-Deletion). Pushing of the log files and deletion of the log files do not go hand-in-hand so the issue you are encountering could just boil down to making some configuration changes for pushing and deletion.
A second option you could do is just have Web Reporter pull directly from the location that MWG is pushing to (the FTP site). This would be configured in Web Reporter for the Log Source. You would set it to collect log files from a 'FTP server' instead of Webwasher.
Did my answer help you in figuring this issue out?
Do you have to set up logging rules or is it enough to just configuring the gateway to push to the reporter. I can see the files in the jobs on the reporter but there are no hit counts or stats on the main page of the reporter ?
The logging rule is used to define what data you want logged. Without the rule, there is no data in your log, so yes, it is necessary. If you attach a screenshots of all the configuration screens, we can check them for you.