I think the issue here is IE8, correct? It works fine in all other version browsers ..
To answer your question ... there is no magic setting to fix IE8.
Scott.
When I optimized my application for IE8, I understood, that there is no magic for IE8... I did everything, that is possible. I think, there is no fix for that problem... IE8 is IE8...
23k of records on an 80 column grid without any type of pagination/buffering that creates "laggy scrolling" is not a reasonable requirement. Especially when you are targeting multiple platforms. Requirements are easy to make, but it doesn't matter if it can't be implemented. You need to rethink how you are architecting the application. A user can only see and understand a tiny fraction of that amount of data. If you need to do calculations for it, do it serverside and send back what is relevant to the user.