jQuery Grid Plugin - jqGrid

I'm not sure if this a bug or something I'm doing wrong, but in some circumstances in IE8, when selecting a row in the grid, the grid "hops" down a little and I get a whitespace line above the TH row in the grid. I cannot inspect select or otherwise mark this phenomena in IE to determine where exactly in the DOM it comes from. I did notice a tiny little mark appearing in the upper left corner of the grid (right where the rounded edge is in Firefox) under the same circumstances and suspected that the two behaviors were linked to the same underlying cause, just manifesting differently in the two browsers.

For the record, the IE problem is the only one I'm concerned about both because it's clearly a noticeable quirk and because the solution I'm building will run primarily in IE.

Using Firefox, I was able to track the stray pixel to a new element being inserted as the first child of "_gview":

I don't know what this element is or does, but I do know that if I destroy it the quirk dissapears. I use $('#_kn').parent().remove() to to the dirty deed because there's no way for me to query for the parent element (hence searching for its child and then jQuerying the parent) Can someone tell me what the purpose of this span is? Can I prevent it from coming up in the first place? Can I prevent it from displaying at all using a preventative measure such as a CSS rule (I don't see how if there's no tag or class…) Also, dor some reason this behavior is not consistent and I have not been able to create a new page that exhibits it, although my existing page always consistently exhibits this visual quirk.

I'm using jqGrid 3.7.2
jQueryUI 1.8.2
jQuery1.4

Many thanks in adv. for any insight into this issue