Old post, but I think you need a <space> character in the text in order for SW to break to another row.
Also, I had the problem where the "ITEM NO." would NOT break to another row, no matter how I dragged the columns. Looks like if there are any merged cells spanning across the cell/column you want to resize smaller, then I need to hide those merged cells (e.g. header row), resize the column, then unhide the merged cells row.
Double click the column heading, delete the space (between two words) and add the space again. Thereafter, you are able to recreate the "wrap text" condition.