kajaeger,
I was able to produce the same end result as yours, by going into "Format Cells", choosing "Custom", and entering a "space" character under "Type".
Is it possible this might be your situation - i.e. where somehow your formatting got changed to such a "Custom" format ?
If so, you only have to change the formatting back to a regular format, or to "General".
Hope this helps.
Regards, ...Dale Watson dwatson@bsi.gov.mb.ca