If the projects you are trying to check in or publish appear to be stuck, something may be blocking the queue. The first step to resolving this issue is to look for projects in the Getting queued state.
To view the jobs currently in the queue, click Server Settings on the Quick Launch in Project Web Access, and then click Manage Queue on the Server Settings page. If the list of jobs is long, you may find it helpful to filter the list of jobs by status, looking for jobs in the Getting queued state.
When reviewing jobs in the Getting queued state, don't forget that some actions, such as checking in a very large project over a slow connection, may take quite a while to process. Before proceeding with the next step, be sure that the job is actually blocking the queue and not just processing slowly.
Once you've identified the job that is blocking the queue, the next step is to cancel the job. By default, jobs in the Getting queued state are protected from being canceled. You can turn off this option, but be very careful when choosing what you cancel. When you cancel a job in the Getting queued state, you will lose any changes you made since the last time you checked the project in.
If you are sure that you want to cancel the blocking job, in the Advanced Options section, select the Cancel jobs getting enqueued option. Then, select the job that is blocking the queue in the Jobs Grid, and click Cancel Job.
With the blocking job now canceled, the queue should resume processing subsequent jobs.
For more information on queuing in Microsoft Office Project 2007, take a look at the following: