Datatable moves up and down in IE 7 & 8

Support,
When selecting to sort any column in windows 7 - ie 7 & 8, the Datatable moves up and down when sorting. Firefox seems to be good, it seems that this only happens in IE. On a Mac Firefox or Safari work well. Any ideas what could be causing this issue.

Thanks,

64coach

http://www.newjerseysepticservice.com/table/gmjr-full.html