We've starting using checksum in civimail for membership renewals. The checksum link takes the user to a webform in which they can renew.
When they do renew the membership is being recorded as a new membership wiping out the member since date.
For example, one person has been a member since 2010. Now it reads 2016.
Anyone know why this is happening.
Thanks, Andy CIVICRM 4.5.8 Drupal 7 We've updated webforms and webforms-civicrm to latest version