Fails to calculate pages to print

Has anyone come across this before, and if so did you discover why it did this?

An Excel (2003) document only contains 143 rows and 4 columns, ask it to print it goes to 4 pages, tell it to fit to 1 page wide by 3 pages tall it still calculates that as 4 pages, add a few more rows (eg 146 or 147 total length) and it then calculates the pages correctly and fits it to 3 pages.

Alternatively, if I leave it as 143 rows and tell it to Adjust to 95% it then calculates it as 3 pages.

It's not a major hassle for me but I sure am curious and would love to know what causes this blip

As ever thanks in advance for any help

Mossy