I'm having the same issue as well. I contacted tech support, and after stripping out some custom css at their behest, and waiting until they said they's fixed it, it started happening again. I changed templates, and it still happens. The only thing that makes it work is to log in to the website, and change the display of the archive contents. Then when it happens again, change it back to what it was before!
This is a real pain, and happens with or without custom css.
Has anyone found a solution please?
Thanks.
Terry