I love the new column sorting features in the Virtualmin theme. However, they do not sort properly on numeric fields. For example, sorting on Disk Quota Used or Mail File Size groups all of the numbers starting with "1" first, then "2", etc., regardless whether it is 1 KB or 100 MB. The actual size needs to be taken into account and sorted numerically for this to really be a useful feature.
Column Sorting Alphabetically vs. Numerically