I migrated to Excel 2007 about 6 months ago and whilst there are a number of significant improvements, I am continually getting problems with loss of format, even within relatively simple spreadsheets.

The symptom is that in some circumstances when a spreadsheet is reopened after being saved, or is opened by a collegue, using 2003, the format of the data has changed. Typically all data will now be dispalyed as accouting format, for example 0 is displayed as "- !", whereas previously it could have been in currency or number format, eg £0.00. in addition Pivot tables lose some of their format and cells which have been highlighted by colour lose those colours. Once this has happened then even after changing the format back to currency and resaving then the next time the file is opened it is displayed as accounting format

having been frustrated with this for some months, I have identified the problem appears to be caused when you have two instances of excel open in separate windows and you copy data from one to the other. Occasionally when you paste the data, the pasted cell appears blank. Once this has happened then the file will be changed next time it is saved

Is this a known bug in excel 2007.