Is This Normal or a Bug

[Gamerear21]

So I updated to malwarebytes 3.0 and after install checked for updates till it said there was none. I went to run a custom scan and selected all the options like rootkits and memory objects and then selected all my partitions and at the end of the scan it showed only 190,625 files were scanned. There should be a lot more, malwarebytes 2.xx always found around 450,000 and so does my antivirus norton security. So I the  decided to try threat scan instead of custom and it scans 364,560 files which is better but still not all my files. Is this normal or just a bug that version 3 is not scanning my whole system like 2.xx ? 

[Gamerear21]

So i just tried this on my windows 8.1 computer and again on my windows 7 laptop and both have issues not scanning the entire system during custom scan with all the partitions selected with the lastest version and latest definitions. Anyone have any suggestions?