I've seen this happen before. Cleaning it up was a pain and I forget all the details. As I recall, we had to export the data in the table to a text file, then re-import the data. If memory serves, it inolved using unusual separaters such as the . character you are using and specifying that format in the Computer's system formats.
thanks for reply
I have since tried the file on another computer and it works fine
so it looks like the file/database is ok - I think FM must've picked up a bug on the first computer
i think i will try deactivating fonts and then re-installing FM, and see if that solves it
Check the system settings for dates on the first computer and see if any are different from the one where this works.