FAQ 92 has a lot of reasons why people can't see their entries, but it leaves out an important one: people being logged out due to cookie problems.
* If you are not logged in, try logging in (http://www.livejournal.com/login.bml) and going to your journal page. If the entry now appears with an icon of a lock or an eye, or the notation "Security: Friends" or "Security: Private", you've set the security level of the entry to 'friends only' or 'private'. See http://www.livejournal.com/support/faqbrowse.bml?faqid=24 for more details on security levels.
* If you are not logged in, try logging in (http://www.livejournal.com/login.bml) and going to your journal page. If the entry now appears with an icon of a lock or an eye, or the notation "Security: Friends" or "Security: Private", you've set the security level of the entry to 'friends only' or 'private'. See http://www.livejournal.com/support/faqbrowse.bml?faqid=24 for more details on security levels.
*If you rarely or never see Security: Private entries on your own journal and Security:Friends entries on your own journal and Friends page, then you may be getting logged out accidentally. For more information on dealing with this problem, please see http://www.livejournal.com/support/faqbrowse.bml?faqid=162