On going over my "new" 745 purchase, I have noticed that the screen between the wipers appears to have fallen away from the vents. It seems to me that it is necessary to keep debris out of the ventilation system.
How do I fix this problem?

Thanks for your help to Rtilghman, Colin UK, and Erwin. I realized this morning, that the reason I bought another Volvo is because of this resource.
What a great source of information!
I find that after 18 months of ownership, I can offer my own description of how I handled a situation with one of our 2 Volvos.

Once you get it done IPD is selling these sexy vent covers (snow covers) that keep larger debris from falling onto the grill.
--
Erwin in Memphis, '95 855t

Remove both wiper arms by lifting the plastic cap over the spindle and undo the nut which holds the arm onto the spindle. Do this with the arms in the parked position so you know where to position them when refitting. Pull off the spindle to panel rubber seals.
Open the hood and you will see three bolts holding the panel to the firewall, remove these and lift the front of the panel up and forward towards the rear edge of the hood, it will unhook from under the windshield and lift off. The mesh screen is just glued to the underside of the panel with some black muck.
Clean it up and re-glue with something suitable.
Reassembly is the reverse of dismantling as the books always say.
A good idea would be to put masking tape on the rear 3inches or so of the hood to avoid paint damage.
Hope this helps, Colin.

The screen you mention is attached to the underside of the cowling with this black epoxy goo volvo used all over our vehicles. You can also find it around the widnshield, etc.

To reattach it you have t remove the cowling from the car, flip it over, and reattach the unit somehow to the cowling. You might strip it and glue it, you might tie it up against the cowling with metal wire, or you might use some new epoxy. On my brick I just pulled on the existing epoxy and remashed it all together. I then stapled it (yeah, staples) over itself over the grill and duct taped the ends. It's actually worked amazingly well and hasn't moved in a year. I just couldn't think of a better way to reattach it quickly with the limited matericals I had on hand.

As for whether it's necessary or not... the cowling grill (not the screen) keeps out most of the big stuff. The opening for the air/intake system (that runs down to teh heater blower) is actually well protected by being up off the bottm (there's a 2" or so lip) under a secondary plastic cowling. There is the possibility that stuff could get sucked into the blower, but it isn't as likely as you think (water is a bigger danger)

The reason I wanted the screen in place is a bigger problem you might not think of. The area under teh cowling runs down the side fo the car behind the "volvo" patch and into the hollow runners under the doors. This is supposed to serve as a water drainage system. However, if the debris that falls in the cowling gets down there it can allow water to pull or get wet and rest against the metal. This then causes the whole thing to rust frm the inside out. It actually happened on my brick... I've got a big hole (2") under the passenger's door a a result. Blame volvo for the bad design.

-rt