I made a point of installing the Safari 5.1.2 update during the week, but was disappointed to find the 'white flash' problem was still present. If the delay was always so short that it deserved the term 'flash' I wouldn't be so bothered, but it often lasts several seconds.

If you have multiple pages open in tabs in a browser, the content should appear instantly when you click on a different tab. But that's not how recent versions of Safari have behaved. Instead, the tab content sometimes disappears leaving an all-white window, and then the content reloads either from the cache or in some circumstances from the server.

Safari 5.1.2 was supposed to fix that - or at least the "issues that could cause webpages to flash white" - but it doesn't make a reliable difference on my Mac. After emptying the cache, I did see some improvement, but when I opened 13 tabs from a bookmark folder and then used another program while they loaded, I found that clicking on any of the tabs gave a white window with a spinning progress indicator showing the content was being reloaded. Sometimes merely making Safari the frontmost application is enough to trigger a white window.

So Safari 5.1.2 is better in that I don't see white flashes quite as often, but it still happens to an irritating extent, especially as it didn't happen at all in Safari 4.x (or 5.0, as best I can remember). I haven't carried out methodical tests, but it appears to be worse when there's little free memory.

I'll close with an item from the 'it's never too late to learn' department. I read this week that control-K acts as 'delete to end of line' in many (most?) Mac programs, and has done so since Mac OS X 10.0. Apparently this and some other Emacs commands (eg control-D for delete) usually work while typing, whether that's in a browser's address bar, a TextEdit document, an Outlook email, or while changing a file name in the Finder. Not surprisingly, Word is an exception.