I have timing data from a stopwatch.

The readout can be displayed in two ways:

1. Up to 40 minutes, the display contains mm:ss:dd, where mm =
minutes, ss = seconds, and dd = deciseconds (100ths of a second, not
milliseconds).

2. For 40 minutes or more, the display shows hh:mm:ss.

I would like to enter the raw data in a Stopwatch cell and have it
display as it was recorded from the stopwatch and then convert it to
minutes in a Minutes cell. Most of the times will be well under an
hour.

Some examples:

 Stopwatch    Minutes
  30:00:00     30.000
  30:10:00     30.167
    30:30:00     30.500
  30:30:10     30.502
  30:30:25     30.504
  30:30:50     30.508
  30:30:99     30.517

I formatted the Stopwatch cell (A1) as "mm:ss.00".

In the minutes cell, I put "=A1*24*60".

This works perfectly except that when I select the Minutes cell, the
contents displayed in the formula bar are missing the deciseconds. If
I enter "30:30.99", it displayes in the cell as "30:30.99", but in the
formula bar, it shows "00:30:30".

What is going on here?