I need help using the Vissort plugin to visual block sort numberically.
The [documentation](http://www.drchip.org/astronaut/vim/doc/vissort.txt.html) states that I can use the 'VSO n' command to set sort to 'n' for numeric but I'm having no success. 

I'm on a windows machine.

The below example only has one column, but in the real world I need to be able to numerically sort on any column within a text file. For now my work around is using '!gsort.exe -k 10 -n' to sort by the 10th column.

After using 'VSO n' and running Vissort, this is how my list is sorted:

```
1 
11
13
15
17
19
2 
21
23
25
27
29
3 
31
33
35
37
39

```