seems like that should have been easier to figure out... anyway, i drove it for about 8 mi in 4th and then engaged o/drive. i immediately deselected it and got no response. if i let the car sit for an hour or so. o/drive disengages. the manual (and Duane) caution not to reverse when stuck in o/drive. Pretty sure i haven't, but if i did, i hope i dinn't screw it up worse.... the haynes manual lists:

wiring
control valve (i think this is integral to the soloniod)
unidirectional clutch sticking
mechaniucal damage to the unit.
...
pretty sure its not wiringor o/drive switch as the light comes on and goes put when its supposed to.
the switch on the gear box may be a suspect if such a thing can be heat related.
not low oil as this has been changed a few times in the trouble shooting process.
the haynes manual does not list the soloniod a a possible for o/drive not releasing.
it does list the comntrol valve(i hope thatis also called the operating valve as the volvo service manual says that is integral to the soloniod.
...
there is a small section in the volvo manual that describes solonion removal and reinstallation... it says to replace the 'o' rings.
it also describes cleaning the orifice nozzle and checking and replacing the check valve.
the filter was cleaned.
all this can be done w/out removing the o/drive unit...
...
sooo, i hope its the above procedures wii help, if not then i need a soloniod..if still no good, looks like the o/drive unit will have to come out..
(could be a sticking unidirectional clutch).
...
so there it is...any inputs will be appreciated.
flaps