Quick fix: locate spdatasource, function readpage and remove line
setSessionVar($this->name.'_currec', $offset+$reccnt);
The use is limited btw. If you select a record in the grid this record is then set into the form. But not the other way around, which means that you can scroll out of the grids view. To avoid that, you can consider removing the next/prev/first/last buttons from the toolbar.