So, the best solution to check AeroPlan flights is:

NOT to call AeroPlan and wait 40 minutes, & NOT actually get to speak to anyone;

NOT to use ther terrible AeroPlan web interface. Shows availability one minute, and 10 seconds later the flight is gone, then 10 seconds later it's available again!! Or "we don't fly to that city", yet it just offered me a flight there?? INTENTIONAL Glitch heaven.

DO Call UNITED Airlines or any StarAlliance Airline; and they can check on ALL StarAlliance flight availability for you.
Unfortunately, you'll still have to try and book with AeroPlan... but it will save your Hours upon Hours of hassle and failure dealing with AeroPlan.