Welcome to the forums, dancinmoonlit. Just to be clear, I wasn't suggesting that low quality backlinks are a Panda factor. Instead I was using that as an example of another kind of algorithm change that can lower rankings.
That's not to say I've ruled out backlinks as a possible Panda factor, too. Did your ranking losses occur on the exact date of one of the Panda Updates? - Feb 24, Apr 11, May 10, Jun 16, Jul 23, and Aug 12 are the ones Google commented on.