Hi, I checked this with three browsers on my machine ( Chrome, Firefox and IE) If a package has multiple vignettes on its package landing page, All the links for the vignettes are collapsed and displayed next to only one of them. This is happening in both devel and release. For an example, see: http://www.bioconductor.org/packages/devel/bioc/html/GenomicRanges.html http://www.bioconductor.org/packages/release/bioc/html/GenomicRanges.html and - http://www.bioconductor.org/packages/release/bioc/html/Rsamtools.html
Thanks and Regards, Sonali