I've just released DataTables 1.4.3 which includes a number of bug fixes (thanks to all who reported them). These fixes are all back ported from the 1.5 beta series (and as such are all fixed in that branch):
New (back ported from 1.5.0 beta 4): Added option for using original data for sorting and filtering (when using fnRender) - bUseRendered ( http://datatables.net/usage#bUseRendered )
Fixed (back ported from 1.5.0 beta 4): $ and ^ are escaped as regex characters now
Fixed (back ported from 1.5.0 beta 4): Filtering with a string as anything but a post fix filtered on the old result, rather than the full table.
Fixed (back ported from 1.5.0 beta): sClass is now applied to DOM read cells as well as dynamically created ones
Fixed (back ported from 1.5.0 beta): sAjaxSource didn't do an initial sort on the retrieved data
This is effectively a stabilisation release for the 1.4 series and is likely to be the last 1.4 release (unless there is something seriously wrong!)