Turning OFF IPv6 on 10.6.8 returns browsing speed to normal & more...


Turning OFF IPv6 on 10.6.8 returns browsing speed to normal & more...
Recently installed 10.6.8 on my MBP and had same problem many reported with unbearably slow browsing on all browsers (Safari, Firefox & Chrome all took 10sec+ to load Google's home page with beach balls spinning along the way).  Also many apps where slow to even open.  Really noticed a problem with iTunes - which for me runs a bit sluggish anyway as my music library is over 2TB with 275,000 songs.  With iTunes it would do the beach ball jiggy for 30sec sometimes when just scrolling the library.
Anyway, to make a long story short did all the usual of Repairing Permissions, etc - but same same.  Then remembered in the 10.6.8 release notes Apple made changes to the IPv6 protocol so turned it OFF for both my Ethernet and Wireless  (Network->Advanced).  And WAL-LA.  It is like a whole new machine with browsing back to lightning speed and even iTunes is working like never seen it before.
Hope this may help others facing similar grief... But also curious on why this would be the case...
Btw  - forgot to mention since last couple of updates could not AirPlay anymore through my AirportExpress.  When I tried to connect to the remote speakers it would sit there for about 20sec showing it was trying to connect then stopped.  Connection from to AirportExpress was no issues.  As with the above, after turning off IPv6 - all working fine as well.
this should help
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