Starting in Altru version 4.9, a Membership Comment note is not automatically created when selling a new membership to a constituent, as is was in earlier versions- see screenshot: User-added image  

Below is the new workflow for adding a constituent membership note:
  1. From the constituent record, click the Memberships tab
  2. Click on the hyperlinked name of the membership
  3. Click on Other Tasks
  4. Click on Edit Membership Details
  5. Enter the note here, and it will be added in the Membership Comments section