Trying to fix corrupt Adobe PDF files

The company I work for uses an online document management system and like to work with large PDF files (I recently worked with a 353 page, 17 MB problem PDF). Too often, we have PDF files have problems or have pages get corrupt. I haven't found a cause or a solution that always fixes the problems, but here are some methods I have found that work (my reference is Adobe Acrobat 8 Pro).

Use Preflight to check the PDF for syntax issues (requires Acrobat Pro or above - and I haven't found out what to do with this information):
Click Advanced -> Preflight... in Adobe Acrobat Pro
Expand PDF Analysis, select Report PDF syntax issues, and click Execute.

Remove the Tags in the document (requires Acrobat Pro or above) :
Right-click the Navigation Pane and click Tags
Click the root of the Tags tree
Right-click Tags and click Delete Tag
Save

Reduce File Size (Acrobat Standard or above):
Click Document -> Reduce File Size...
(you can adjust the Compatibility level of the file)
Click OK
Save as a new file name and click Save

Use the PDF Optimizer to remove features (one by one or all then all minus 1, then all minus 2, etc) (Adobe Acrobat Pro or above):
Click Advanced -> PDF Optimizer...
Click the checkbox next to unnecessary settings or settings you would like to try to remove for troubleshooting purposes
Click OK
Save as a new file name and click Save

Try resaving the document using Nitro PDF Reader (this has worked for me many times):
Open the document in Nitro PDF Reader
Click File -> Save As -> PDF Document
Save the file using a different name and click Save

Delete bad pages (either one by one or as a group, if necessary) (Adobe Acrobat Standard or above):
Open the problem PDF in Adobe Acrobat
Click the tool "Click to show one page at a time"
Page through the pages in the PDF, note any page that gives you an error message.
In the Navigation Pane, click Pages. Select the problem pages, right-click, and click Delete Pages...
Click File -> Save As, save the file using a different name, and click Save

Export as PostScript without comments, export comments, convert PostScript to PDF, and import comments (you lose bookmarks using this method) (Adobe Acrobat Standard or above):
Click Comments -> Export Comments to Data File..., give it a name, and click Save
Click File -> Export -> PostScript -> PostScript
Click Settings and uncheck Include Comments, click OK, give it a different name, and click Save.
Open the PS file in Adobe Acrobat.
Click Comments -> Import Comments..., select Adobe FDF File from the file types drop-down, click the FDF file, and click Select.
Click File->Save.