Member Since: Oct 27, 2005
01-19-2007, 05:04 AM
G'day Rosy720 & welcome to Mac-Forums.
Have you ejected the Ubuntu disc? What happens if you return to the Sys Prefs>Startup Disc, and select your HD?
Have you restarted your Mac?
Bypass Startup Volume
When a Mac is turned on or restarted, it attempts to load the operating system from the default volume selected in Startup Disk preferences. However, if you want to temporarily bypass the primary startup volume, press Command-Option-Shift-Delete at startup and the Mac will look for the next available volume (such as an optical disc or external drive) with a valid installation of the operating system. This does not affect the setting of Startup Disk preferences.
Start up in Safe Mode
Under Mac OS X 10.2 and later, you can enter Safe mode by pressing the Shift key during startup until "Safe Boot" appears in the progress window. Like starting up in Mac OS 9 with extensions and control panels disabled, Safe mode allows you to eliminate many potential sources of problems, thereby narrowing in on the cause of any trouble you suspect is related to items loading at startup.
Starting up in Safe Mode:
Performs a directory check of the hard drive identical to clicking Repair Disk in the First Aid pane of Disk Utility.
Ignores kernel extensions cache (/System/Library/Extensions.kextcache).
Loads only required kernel extensions (/System/Library/Extensions).
Runs only Apple-installed startup items (/Library/StartupItems and /System/Library/StartupItems).
Loads only those fonts in /System/Library/Fonts (Mac OS X 10.4 only).
Trashes all font caches stored in /Library/Caches/com.apple.ATS/user ID number (Mac OS X 10.4 only).
Disables Login Items (Mac OS X 10.4 only).
Because Safe mode checks (and repairs, if needed) the directory of the Mac's startup volume, startup can take considerably longer than normal, especially if you have a large hard drive. Let the startup process run its course, lest you compound a bad situation by restarting during the lengthy disk repair.
Once the Finder appears in Safe mode, restart normally and see if your problem is gone. If so, the disk directory repair did the trick. If not, restart in Safe mode again and see if the problem is gone. If so, then the problem lies with files that aren't loaded in Safe mode, such as kernel extensions caches, non-Apple startup items, etc. Use trial and error to find the troublemaker.
When you're running in Safe mode, you can use your Mac normally, with the caveat that some things will not work. For example, you can't use an AirPort card, some audio input or output devices, or USB modems because the resources required by these devices are temporarily unavailable.
If pressed immediately at startup, the Shift key allows you to enter Safe mode as just explained. Pressed later in the startup process, it temporarily disables login/startup items specified in Accounts preferences.
If your Mac is configured to automatically login as a particular user, press the Shift key when the blue background with the progress bar appears during startup. This forces the login window to appear. Log in as the desired user, then immediately press Shift again until the Finder desktop appears.