Lost formatting in tables

[Wrecks]

Welcome beginner. Please answer all of the questions below which may provide information necessary to answer your question.
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2.3.1, XP Home:
When I tell Office to format a table cell in Writer for numbers, enter formulas---like to have NEVER figured that one out---save the file, reload it---or just change a number while it's open, the formatting just goes away. I spent an hour figuring out how to and entering formulas in table cells, only to have all of them lost because it reverts back to the default, even with the cells protected. Unprotected cells formatted for two decimel places lose it when you change the number in the cell---reverting back to text, and any cell with a formula: byebye.
I know this must be pilot error, but I cannot figure it out.
Any help will be greatly appreciated.

[foxcole]

What do you have set in Tools? Options> OpenOffice.org Writer> Table> Number recognition?