jQuery Grid Plugin - jqGrid

I am using jqGrid to render a tree which is working fantastically!  Thanks jqGrid & Tony!

I've been instructed that for 508 compliance, the app needs the ability to tab through all the cells in the table, but since the tree is non-editable when I try to tab around the page, the browswer skips the table entirely.  Essentially, I need to be able to navigate through each cell left to right, and on down through the entire tree (via tab or possibly other keystrokes).  But, I don't want to have to enable editing or something like that in order to fulfill this requirement.

Anyone have ideas?  I've tried searching the forums for the answer, but didn't find anything helpful.  I'm really hoping that I can come up with an answer because there is a lot of time invested in/with jqGrid that I'd hate to throw away.

Currently using version 4.2 but looking to upgrade to latest...

Thanks!