Why new 32W circular fluorescent light bulbs keeps getting blown?
It's the ballast

When old magnetic ballasts go bad, that's one of the things they do.  I swear, I'm about ready to stick a logbook inside every fixture because I think most of our bulb replacements are in the same 5 fixtures. 

Decide which type of bulb you want going forward (T12 vs T8) then buy an appropriate electronic ballast.  

If you want to play around with some of the new LED "tubes" or fixtures, those should last 20 years... but there is also a lot of cheap junk out there that really won't.