Powerpoint won't read CS TIFF file

I have long used Photoshop 6 to scan in images, edit them, save them in TIFF format, then import them into MS Powerpoint. I recently upgraded to Photoshop CS. Now when I try to import TIFF files created in Photoshop, Powerpoint gives me a box asking me what format I want to convert the file from: "Convert file from:", then a list. I have to go back, reopen Photoshop 6 (which, for some reason, CS did not overwrite, so now I have both versions on my computer), open the TIFF file, and resave it. Then Powerpoint will accept it.
As far as I can tell, I've got all the settings in both versions the same. Any ideas?
Thanks,
Robert

Are you saving layered TIFFs? What version of PowerPoint?

As someone who uses images all the time in PowerPoint, may I suggest you use JPGs instead? TIFFs will explode the size of the PP file with no benefit whatsoever.

Bob

Hi Robert,
I don't know what layered TIFFs are--how do I tell? I'm using Powerpoint 2000 SP-3. Thanks for the tip on using JPEGs though--I'll probably do that, though I'd like to figure out what's causing the other problem.

Robert

Layered TIFF are very similar to PSD files. They contain layers and transparency. I don't know if PP can handle them because I never use TIFFs in PP.

Bob

Are you saving with compression? I seem to recall a problem with PP reading compressed TIFFs saved in PSCS.

I think default was LZW compression--I'll try it with no compression. Thanks