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 and subdomains.
* 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. This is especially likely if you are accessing your LiveJournal through your paid account subdomain (http://www.livejournal.com/support/faqbrowse.bml?faqid=131). For more information on dealing with this problem, please see http://www.livejournal.com/support/faqbrowse.bml?faqid=162