Missions vs Walkers

Guys... The walkthrough says the base demo is A1 M3...i just played it as A1 M5...next is gunstar whatever A1 M6---are my sims hammered or is the walker wrong...ive got the patch, and everythings going together ok sofar...does this happen often..i honestly thought it had skipped A1 M3---but it got thrown in there just fine.
I must say im really getting locked in...didnt touch my other sims all weekend : )

The Acts and Missions in the Walkthrough are correct. Maybe you're getting confused with the side missions that can come up from time to time.