Missing columns from Excel to Numbers?

Hi guys,

Just opened a large Excel spreadsheet in Numbers (v 3.5.2 (2118)) on a brand new MacBook Pro. Until now I've been using Office for Mac but thought I'd give the apple versions a go. Generally, so far so good, but...

This particular spreadsheet stops at Column IU when I open it in Numbers, but in my original excel spreadsheet it went well beyond that, so now I have missing data and fields.

There is no actual formatting, macros or formulas in any of the spreadsheet, it is all basic text and manual data entry (just a LOT of it). I have un-hidden all the columns, but have had no success in retrieving them.

Is column IU the limit?

Any help would be great!