Edit: After half day, my wife’s Mac started having the same problem. I have then applied the solution that I found in the Apple
Bug Fixes Released in Safari 5.1.2 –
Apple earlier released Safari 5.1.2 to the public, it is available direct download or by opening your software update. Do not expect from this update but it does fit a lot of bugs such as the issues of stability, extensive memory usage and fixing flashing white webpages.
This update contains various improvements, including fixes that:
- Improve stability
- 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