There are a number of example problems arising in triple-deck theory which we have attempted to solve recently where the solution technique seems to generate unexplained behaviour. For example in the classic supersonic compression ramp problem discussed in Logue et al (2014) wavepackets appear in the results which do not appear to be related to anything physical. A similar situation arises in trying to solve the classic initial value vibrator problem of Terentev (1981). In this talk we will show some more unexplained behaviour for this test case but where the ‘true’ results are well known.