Take a look at the following image. The column is Maximum time. It's got 4 values for '0.0000'

Now click on the filter button. You get what's shown in the followig picture. The filter has got 2 entries for '0.0000'

Now select the first entry. 3 records are returned as shown in the following picture.

On selecting the second entry 1 record is returned as shown in the following picture.

Now if you apply the custom filter for '0.0000' no record is returned.
Now click on the filter button. You get what's shown in the followig picture. The filter has got 2 entries for '0.0000'
Now select the first entry. 3 records are returned as shown in the following picture.
On selecting the second entry 1 record is returned as shown in the following picture.
Now if you apply the custom filter for '0.0000' no record is returned.