There are several reasons why your entries might not be showing up as you intended. Here are some of the most common:
* If your entry is viewable in your own journal but not on other users' Friends pages, the problem may be that it was backdated. (Backdated entries always appear in the Calendar and Day views, and will also appear in the Recent Entries view if the date is within the range currently appearing on the page.) See http://www.insanejournal.com/support/faqbrowse.bml?faqid=55 for more information on the "backdate entry" function.
* If the entry can only be seen on your friends' Friends pages, the entry is most likely misdated. Look at your journal page and carefully check the dates (including the year) of the most recent entries that appear. See http://www.insanejournal.com/support/faqbrowse.bml?faqid=67 for more details.
* As InsaneJournal grows, the number of posts being handled at the same time also increases in scale. At any one time, there may be dozens of connections open to the servers, and within a few minutes, as many as few dozen journals may be updated. There may be a bit of lag between when you post an entry and when InsaneJournal is ready to display it. Refresh your page after a few seconds to see if this corrects the problem.