When setting up a SharePoint Shared Service Provider (SSP) for the first time in a new web farm (or any other time really) you can sometimes run into the "Provisioning In Progress" issue where SharePoint will tell you there was an error with the text below.
<blockquote><em>Shared Services Provider creation failed
Reason: No running instances of Shared Services Provider provisioning job
service are online

Check the event log for details.

Note: SSP provisioning will be retried periodically. If you correct the
error that caused this failure, provisioning will subsequently succeed. To
stop provisioning from being retired, delete the SSP.<!--more--></em></blockquote>
This is said to happen when the databases and the file system cache get out of synch for some reason.  Corruption,  Incomplete Installation or Removal, etc...  The first thing you need to try is deleting the File System Cache.

Do this by following these steps:
<ol>
	<li>Stop the "Windows SharePoint Services Timer" Service on all servers in the farm running it.</li>
	<li>Navigate Windows Explorer to <span style="font-family: Verdana; font-size: x-small;">%ALLUSERSPROFILE% MicrosoftSharePointConfig...</span></li>
	<li><span style="font-family: Verdana; font-size: x-small;">Delete all the files (or move them) except the cache.ini file in this folder.</span></li>
	<li><span style="font-family: Verdana; font-size: x-small;">Edit the cache.ini in notepad and replace the number present with a zero.</span></li>
	<li><span style="font-family: Verdana; font-size: x-small;">Repeat 2-4 for all servers that had the Timer service running.</span></li>
	<li><span style="font-family: Verdana; font-size: x-small;">Start the "Windows SharePoint Services Timer" Service on all servers in the farm running it.</span></li>
</ol>
<span style="font-family: Verdana; font-size: x-small;">This will re-synch the file system cache and allowthe provisioning of the SSP to happen.  SharePoint will automatically retry provisioning on an interval or you could attempt to create a second SSP to test the changes.</span>

<span style="font-family: Verdana; font-size: x-small;">If running WSS3.0.  There is a hotfix that addresses a similar issue to this as well that will need to be applied.  The hotfix can be found at <a href="http://www.microsoft.com/downloads/details.aspx?familyid=A49472F9-93EF-4423-BD0B-06B1B331C7AC&amp;displaylang=en#filelist">http://www.microsoft.com/downloads/details.aspx?familyid=A49472F9-93EF-4423-BD0B-06B1B331C7AC&amp;displaylang=en#filelist</a>.</span>

<span style="font-family: Verdana; font-size: x-small;">Good Luck and leave comments and questions below.</span>