Some times you might apply a patch and the during the process the patch failed at some workers, you search on metalink and find out that you need to apply patch in order to solve this failure, here in this case you have tow options either to cancel the current patch and apply the fixing patch then reapply the patch again or you can do the following (apply the fixing patch without the need to reapply the first patch and its very helpful when you applying a huge patch).
This is based on note (175485.1)
Steps to do that are:
1. Using the adctrl utility, shutdown the workers.
2. Backup the FND_INSTALL_PROCESSES table.
3. Backup the AD_DEFERRED_JOBS table.
4. Backup the .rf9 files located in $APPL_TOP/admin/
5. Drop the FND_INSTALL_PROCESSES table and the AD_DEFERRED_JOBS tables.
6. Apply the new patch.
7. Restore the backed up .rf9 files.
8. Restore the FND_INSTALL_PROCESSES table.
9. Restore the AD_DEFERRED_JOBS table.
10. Re-create synonyms for APPLSYS.AD_DEFERRED_JOBS and APPLSYS.FND_INSTALL_PROCESSES.
11. Start adpatch, it will resume where it stopped previously.
and as you all know Oracle is not Magic, it just takes years of experience ;-)