Travel with AP: Secondary inspection for EACH re-entry?

[NJ-NY]

Yesterday I came back from Canada (Quebec) and at Neewark airport I was asked to step aside and have a secondary inspection. I thought this was done only the first time the AP is used. Two months ago I travelled to Toronto, did the INS crossing at the Toronto airport with my AP that I had used previously and no one asked me to do anything.

Why is this?
Is secondary inspection required for EACH re-entry into the USA when one has the AP?

Thanks.

 

[dms]

In my experience of using AP multiple times at multiple different airports, I've almost always been sent to the secondary inspection area but I think this is because in the majority of cases the primary officers don't have the necessary rubber stamp for AP. The secondary inspection officers usually ask a simple proof-of-identity question such as SSN or mother's maiden name and then stamp the AP. The whole process typically takes less than five minutes.

I did have one entry at Chicago when the primary officer admitted he didn't have the necessary stamp, but rather than sending me to the secondary area, he took me there himself and stamped the AP, leaving a long angry line of people at the desk he had just vacated.

 

[NJ-NY]

I know it takes 2 minutes once they take your case, but usually there is a bunch of complicated cases waiting to be resolved and the policy is 'first come-first served' , therefore the wait can be a long one.

I thought going to Canada and coming back makes things easier since the I-94 stays in the passport if the stay in Canada is a short one. Yesterday they made me fill out a new I-94 a wait for secondary inspection (one hour or so..)

Thanks for your input.