Malwarebytes v1.60

I've just replaced McAfee with NAV on my PC, alongside MWB v1.60 full version. Everything seems to work OK except that every few seconds in the Norton history log the AV reports "Unauthorised Access Blocked" to ccsvchst.exe by mbamservice.exe. I've tried excluding the conflicting files in both NAV and MWB but the messages continue to accumulate. MWB doesn't report that it's been blocked. However, both applications seem to be ignoring my exclusions. Any ideas?