Excel 2007: I had moved the main formula block out of the way, on the same sheet. Then reduced the column & row sizes outside of the work area. Everything worked.
I needed to modify the hidden code, so dragged it back to a workable area. 3 simple cell references were lost in the formulas. =(INDIRECT("'Carb-Data'!"&"B"&BV5))
BV5 was lost (another like this)
CW6 was lost
Clicking undo didn't fix the problem - the data returned to its previous position, but the refs were lost
I simply re-entered the cell references and 'filled' the columns. Everything works again.
I'd like to understand why these cell refs were lost when moving the data, when all others weren't. Eg. =F6&"_N1"
F6 was not lost.