Mac gone insane after downloading software update - help!

[Hermia]

I downloaded the new software updates the other night (via software update) and my mac has now gone insane. The updates were a security update and a quicktime one. Since the updates..

I cannot use the DVD player at all as it crashes as soon as you open it.

I cannot watch videos on iTunes (it crashes when I try).

Safari crashes every time I try to go to www.gmail.com - I don't know whether any other site would crash it too as I gave up and used firefox.

I have never had a problem before with the software updates so I am stumped. Can any nice teccy types help me??!

[Fanriffic]

Try this before seeking further help.

I'm still with OS X 10.4.11 Tiger but it should still apply to Leopard OS X 10.5

Inside your Applications Folder, find the folder named Utilities.
Find an Application called Disk Utility and open it.
Click on your Macintosh HD icon to make it active.
This should be on the left hand side of your window.
Make sure you are on the First Aid tab.
Now click the Verify Disk Permissions button.
After it has finished running the checks -
click the Repair Disk Permissions button.
When this has finished - Quit Disk Utility.
Restart your Mac.

See how you get on with the above.
Post back with results. Someone else maybe able to assist you. Don't forget you can go to the Apple Web Site and click on Support for more help.

[Hermia]

Many thanks - that seems to have done the trick. My mac has always been so well behaved that I haven't had to learn how to resolve problems!

I had a look on some mac forums and other people do seem to have had this problem.