Windows 7 - generic non pnp monitor/extended display problem

I have read this post: Generic Non-Pnp Monitor problem please help

and it seems similar to my problem but not quite the same. Before I proceed, I wanted to ask if the above solution will likely work for my problem.

I have an hp pavilion pc windows 7 with a radeon 5770, connected to two displays. I started up the computer about 4 months ago. The two displays are:

1)a pioneer vsx 1020 a/v receiver (in turn connected to my toshiba hdtv) via hdmi

2)an old (2001 or so) acer 1916 monitor

Everything was working fine for a while. I could control music selection (pandora) on the acer monitor while just having the a/v receiver on and not the hdtv, and it would be in dual display mode (both hdtv and monitor would default to 1280X1024 resolution---lowest resolution between the pair). Or I could extend displays and view hdtv in full ~1920X1000 hd resolution. When I chose extended display settings, it would recognize the acer monitor and recommend the correct resolution per this image: http://www.greenandtheblue.com/homet...desktop_PC.png.

Just a few days ago, I turned on the a/v receiver and the acer monitor (without turning on the hdtv) and the display was just the background and the resolution was too large on the acer monitor. I checked devices and now it shows "generic non pnp monitor". Also, in the catalyst control center settings, it shows the correct monitor (whereas windows config shows generic pnp) but it shows max reported res as 1600 X 1200 which is not correct.
I don't have a problem when I turn on the acer monitor, a/v receiver AND the hdtv...the settings go back to dual display and the resolution is fine. It's a problem b/c I don't want to have to turn on the hdtv and acer monitor just to control the pandora, etc and listen to music via the receiver. Any idea on what's going on? I'm attempting to download new driver for the acer monitor but it doesn't look like there is one for windows 7.

I just would like to go back to the way it was working a few weeks ago.

An addition: I took this screen grab of my monitor output via the program monitor asset manager. I'm wondering if I can glean anything off these. None of the options on the top left show native resolutions of 1600X1200 though. But a few are kind of goofy, the HWP1618 showing 1024X768 which may be a problem. I don't understand why there are so many monitor options though...should be only acer and pioneer correct?



thanks for any help,

S.

I found a solution...first I reinstalled the hp monitor drivers under the hp recovery manager GUI. Then, no sound was coming, so I put default to both ATI Radeon and Realtec sound devices instead of just ATI or just Radeon which was the case when I checked. No idea what happened except maybe HP installed some updates and they wiped out the old monitor driver settings.