Apple today released Safari 5.1.2, bringing several bug fixes and other enhancements. Most notably, it addresses issues with PDF viewing and pages "flashing white".
This update contains various improvements, including fixes that:
Address issues that could cause hangs and excessive memory usage
Address issues that could cause webpages to flash white
Allow PDFs to be displayed within web content
For more detail about Safari, visit apple.com/safari.
UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_2) AppleWebKit/534.51.22 (KHTML, like Gecko) Version/5.1.1 Safari/534.51.22