I have Windows Vista Home Basic running Office Standard 2007

This is my homemade checking account. The balance formula is
I153-G154+H154, where I153 is the previous balance, G154 is a new debit and
H154 is a new credit.

Normally when I fill the resulting balance further down column I, it shows
the balance repeated. This has been working fine from the start months ago.
Today it repeated the resulting balance in the next row, 155, yielded by the
filled formula I154-G155+H155, the latter two being empty cells as always.

Thereafter, rows 156 and following, the correct filled formula is repeated
in column I, but a #VALUE error is returned instead of the repreated previous
balance. The error message is: "A value in the formula is of the wrong data
type." I156 and downward adds a green triangle in the upper left cell
corner. This does not appear in the cells above it.

My eMachine would neither restart not shut down programmatically. I had to
power down manually. Rebooting normally did not solve the problem. What's
going on?