SharePoint University

We have a typical farm installation:  1 web front end, 1 sql server, separate mail server.  When changes are made to pages sometimes it will take a few hours for the changes to actually be visible. 

i.e. We add a link to the top nav bar, which should take effect immediately, and it won't appear until two hours later. 

I have erased my IE cache, reset IIS, reset SQL server, and basically removed anything that could possibly be caching the old information to no avail.  These delays are really hampering development as you could imagine. 

What could be causing these latency issues?  Any suggestions as to how to fix this?

Any chance you have an ISA server in place that is doing caching with your wss box?

There is no ISA server, although one was recommended.  As it turns out multiple people were logging into SharePoint under the same user and making changes to the same pages.  I guess SharePoint just gets confused when this happens.  Also, they had to SP admin permanently logged into another box to run services.  Just bad practices all around.