Photos in Indesign display erratically

Question

Mac G5, OS 10.5.6, 1GB Ram (I know, too littleit's not enough), Dual 2.7GHz Proc.
I've never, in 4 years of using InDesign EVER experienced this prob, but beginning yesterday, I've noticed that photos brought in from PhotoshopCS3 for newspaper print (150dpi) are badly pixelated(sp?). BY default in InDesign, every doc for me opens in a pixelated fashion until I click on the Overprint View, but even after I do that the photo remains in what looks like a lo-res version.
The original photos were 300dpi and much larger physical dimensions. In Photoshop I reduced their overall dimensions and resolution thru the Image Size dialog box. Orig pic: 15" X 24", 240dpi (60MB). New size: 150dpi and 5" X 7.5" (2.4MB).
In InDesign I've gone to View-> Display Performance -> High Quality Display with no results. I rebooted the CPU and it worked fine for about 10 minutes then the problem returned. I even "uninstalled" and reinstalled InDesign with no success. Reset Prefs. The quality of the resolution still goes between bad and good! When the photos display well, they print well and vice versa. I've also switched to Overprint View to delete the lines around textboxes, etc. In the Print dialog box I've made sure in Graphics -> Send data -> All is selected. I've done View -> Display Performance -> Allow Object-level Display Settings.
As I said, it just began doing this yesterday after 4 years of use. There have been no other changes period to the computer in a month. THIS IS PUZZLING not to mention being a major problem! Does the OS need to be reinstalled?

Answer 1

Very good.
I've done that myself sometimes on images. I think perhaps by accidently going to that menu instead of the view menu, or just to see that object.
These things happen from time to time.
I think in the View>Display Performance> there is a way to Allow and Clear Object dislpay settings too.