cursorline performance problem

Hi, I added cursorline to my .vimrc a while ago, I find it very
helpful.

However I also have a jerky scrolling problem, and after debugging
my .vimrc today I found it's cursorline causing the problem.

Is this a known issue? I can't find anything on the web, other than 1
discussion at Experts Exchange which is subscription-only.

:ver below.

Thanks in advance, al.

VIM - Vi IMproved 7.1 (2007 May 12, compiled Jan 8 2009 02:18:41)
Included patches: 1-138
Compiled by buildd@rothera.buildd
Huge version with GTK2-GNOME GUI. Features included (+) or not (-):
+arabic +autocmd +balloon_eval +browse ++builtin_terms +byte_offset
+cindent +clientserver +clipboard +cmdline_compl +cmdline_hist
+cmdline_info +comments +cryptv +cscope +cursorshape +dialog_con_gui
+diff +digraphs +dnd -ebcdic +emacs_tags +eval +ex_extra
+extra_search +farsi +file_in_path +find_in_path +folding -footer +fork
() +gettext -hangul_input +iconv +insert_expand +jumplist +keymap
+langmap +libcall +linebreak +lispindent +listcmds +localmap +menu
+mksession +modify_fname +mouse +mouseshape +mouse_dec +mouse_gpm -
mouse_jsbterm +mouse_netterm +mouse_xterm +multi_byte +multi_lang
-mzscheme +netbeans_intg -osfiletype +path_extra +perl +postscript
+printer +profile +python +quickfix +reltime +rightleft +ruby
+scrollbind +signs +smartindent -sniff +statusline -sun_workshop
+syntax +tag_binary +tag_old_static -tag_any_white -tcl +terminfo
+termresponse +textobjects +title +toolbar +user_commands +vertsplit
+virtualedit +visual +visualextra +viminfo +vreplace +wildignore
+wildmenu +windows +writebackup +X11 -xfontset +xim +xsmp_interact
+xterm_clipboard -xterm_save
system vimrc file: "$VIM/vimrc"
user vimrc file: "$HOME/.vimrc"
user exrc file: "$HOME/.exrc"
system gvimrc file: "$VIM/gvimrc"
user gvimrc file: "$HOME/.gvimrc"
system menu file: "$VIMRUNTIME/menu.vim"
fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_GTK -I/usr/
include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/
usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/gl
ib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/
include/libpng12 -I/usr/include/pixman-1 -DORBIT2=1 -pthread -I/usr/
include/libgnomeui-2.0 -I/usr/include/libart-2.0 -I/usr/include
/gconf/2 -I/usr/include/gnome-keyring-1 -I/usr/include/libgnome-2.0 -I/
usr/include/libbonoboui-2.0 -I/usr/include/libgnomecanvas-2.0 -I/usr/
include/gtk-2.0 -I/usr/include/gnome-vfs-2.0 -I/usr/lib/gnom
e-vfs-2.0/include -I/usr/include/orbit-2.0 -I/usr/include/glib-2.0 -I/
usr/lib/glib-2.0/include -I/usr/include/libbonobo-2.0 -I/usr/include/
bonobo-activation-2.0 -I/usr/include/libxml2 -I/usr/include/p
ango-1.0 -I/usr/include/gail-1.0 -I/usr/include/freetype2 -I/usr/
include/atk-1.0 -I/usr/lib/gtk-2.0/include -I/usr/include/cairo -I/usr/
include/libpng12 -I/usr/include/pixman-1 -g -O2 -O2 -g -Wall
-D_REENTRANT -D_GNU_SOURCE -DTHREADS_HAVE_PIDS -DDEBIAN -I/usr/
local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -I/usr/lib/
perl/5.8/CORE -I/usr/include/python2.5 -pthread -I/usr/lib/ru
by/1.8/i486-linux
Linking: gcc -L. -Wl,-Bsymbolic-functions -rdynamic -Wl,-export-
dynamic -Wl,-E -Wl,-Bsymbolic-functions -L/usr/local/lib -o vim -
lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lpangocair
o-1.0 -lpango-1.0 -lcairo -lgobject-2.0 -lgmodule-2.0 -lglib-2.0 -
lgnomeui-2 -lbonoboui-2 -lgnomevfs-2 -lgnomecanvas-2 -lgnome-2 -lpopt -
lbonobo-2 -lbonobo-activation -lORBit-2 -lart_lgpl_2 -lgtk-
x11-2.0 -lgdk-x11-2.0 -latk-1.0 -lgdk_pixbuf-2.0 -lpangocairo-1.0 -
lpango-1.0 -lcairo -lgconf-2 -lgthread-2.0 -lrt -lgmodule-2.0 -
lgobject-2.0 -lglib-2.0 -lXt -lncurses -lgpm -Wl,-E -L/usr/local/
lib /usr/lib/perl/5.8/auto/DynaLoader/DynaLoader.a -L/usr/lib/perl/5.8/
CORE -lperl -L/usr/lib/python2.5/config -lpython2.5 -lutil -Xlinker -
export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions -lruby1.8 -
lm