Vasoline has been used as long as it has been around. Too handy to ignore.
No pun intended right?
I have had this problem too in the past with this filter. One thing that has helped me in addition to what has already been mentioned. Is when I am connecting the hoses back to the canister. Since it is unplugged I open the valve back up. This allows for the air somewhere to go when it is being sucked back on. I know, it sounds strange but it has helped, at least for me.