I'm getting nicely confused here and would appreciate a little help
please.

For a CD I bought, I had a text file containing details of the
durations of some tracks. It looked like this:
Min Sec
Préambule 02:17
Pierrot 01:58
Arlequin 01:05

I imported it into Excel 2000, where it looked the same.

Adding durations of the first dozen or so tracks gave the correct
answer. For example:

Préambule 02:17
Pierrot 01:58
Arlequin 01:05
Total 05:20

But later totals were clearly wrong. I eventually realised it was
because Excel had assumed, (for reasons I'd be interested to know),
that these were Hours:Mins, instead of Mins:Secs.

So how can I do the following please:

1) Fix this now, after the event. So far, fiddling with changing the
format to Custom mm:ss didn't work.

2) Ensure that future similar imports are correct.

--
Terry, West Sussex, UK