Cannot save document

I am a heavy user of numbers and have repeatedly hit the wall with some of my more advanced spreadsheets. Recently one of my templates would not save as a workable template any longer. I've stopped using it as a template which has worked for a couple months but now when I've tried to make a few more improvements and it is not allowing me to save. This one spreadsheet is the most integral part of every project in my company. I can't emphasize how important it is for me to get this resolved.

Here is the current issue:

In the sheet: "Pricing Backpage" in the table "Proposal Pricing Table" I have tried to enter a new category and it allows me to enter it but as soon as I do the spreadsheet will no longer save. I have a table with 215 rows and "Z" columns and its broken into 5 categories (in the technical table-feature sense of the word). The header row and columns are frozen. I can't think of anything else that would effect it. Almost ever cell in the table has a formula in it. The document size is 6MB.

Error Message:

The document "name" could not be saved.

Another issue I am having is that on occasion numbers will not allow me to copy and paste data. Restarting the application seems to work when that happens but still annoying.

The issue happens on multiple computers within my network. The file is saved on a Xserve Server.

Anyone - PLEASE HELP!

The issue has been reported to apple as a bug.

Thank you.