Stop the automatic format of a time to Scientific

Please can somebody help me?

I have created a data validation list of times in the format hh:mm, but when I select a time from the list it is converted automatically to a scientific format, although the cell is formatted as custom hh:mm.

So for example 01:30 becomes 6.25E02.

I have found that if I format the cell as hh:mm:ss there is not a problem, but I would ideally like the cell format to remain as hh:mm.

Martin,

I forgot to mention that the validation list is in an another sheet, but I cannot see that this would make a difference.

When I was testing the spreadsheet, I'm sure that I did not have this probelm and it suddenly appeared.

I will test on another Pc and see what happens.

Thank you.

Will continue to test.