reloadAfterSubmit: false

    scroll: 1

    rowNum: 100

(Visually I like this configuration the best and the buffer size of 100 is very fast) If you scroll down several pages by dragging the scrollbar and delete a record and if the record is close to the top of the buffer set then it can display a blank grid after the delete:

Other times it may show a partially blank grid like this:

Deleting rows lower in the record set seems to work fine. It appears to do this in both IE and Firefox (I haven't tried others). It looks like it wants to grab records above those currently available set instead of shifting the record set up to fill the missing record. (Perhaps deleting a record near the bottom of the current record set would have a similar problem with the lower portion being blank).