When more than one picasaweb slideshow is embedded on the same page, only the first will load correctly. In the shipping version of Safari, all the slideshows load normally. In the latest nightly builds of webkit only the first.
Confirmed. This works in Safari 3.1. The PicasaWeb slideshows are Flash. Something interesting is the URLs that its requesting: Safari 3.1: http://lh3.ggpht.com/_RVgfDDu2uqk/SMkmUEbJt6I/AAAAAAAA7ww/9tAr_I3IYGo/DSC04337.JPG?imgmax=640 (succeeds) Nightly: http://lh3.ggpht.com/_RVgfDDu2uqk/SMkmUEbJt6I/AAAAAAAA7ww/9tAr_I3IYGo/DSC04337.JPG?imgmax=0 (fails)
Mass closing plug-in bugs, as plug-in support has been removed from WebKit. Please comment and/or reopen if this still affects WebKit in some way.