Hope I can explain this. I am running 6.0.30 trial
From the main screen click filter by and it takes you to page 1 of your default filter. Click on By Year and go to the second page (or thrid, etc). If you select a year then hit the filter button again it takes you back to the default filter but on the second (or third, etc) page. So if you have 1 page for genere and you go back to the second page it is blank. If you filter by artist and go to page 20 then hit filter by it takes you 20 pages into the genere filter so you have to hit previous 20 times to get to page 1.
Same thing if you hit Filter by, then By year (or Artist) and go to the second page (or thrid, etc), don't select anything, hit back to go to the main page. When you hit Filter again it takes you to the default filter but on the second page (or thrid, etc).
I will take a look at this for you now, have you tried the latest trial 6.5 as a lot has been fixed since 6.0.30.