mapserv(): Web application error. Query mode needs a point, imgxy and mapxy are not set??

[John Smith]

guys,
see if you can shed some light:

i zoom in from page A (querying works) with the following cgi
variables set in the url in order- mode, qlayer, map, imgext, minx,
miny, maxx, maxy, imgxy, mapxy

to page B (querying works) with the following variables in the url-
mode, qlayer, map, imgext, minx, miny, maxx, maxy, imgxy, mapxy

then back to page A using the browser back button with the following
variables- mode, qlayer, map, imgext, minx, miny, maxx, maxy, imgxy,
mapxy
except now querying doesn't work and i face the dreaded 'mapserv():
Web application error. Query mode needs a point, imgxy and mapxy are
not set'. but if i then refresh page A, querying works again??

running mapserver version 4.8.3. what gives??

http://mapserver.gis.umn.edu/data2/wilma/mapserver-users/0302/msg00638.html
http://trac.osgeo.org/mapserver/ticket/304
http://trac.osgeo.org/mapserver/ticket/314
http://mapserver.gis.umn.edu/data2/wilma/mapserver-users/mapserver-users.0405
variable order appears right and replacing mapext with map_extent
doesn't help (see above).

jzs