Printer not recognized after one print in PS CS4

I just replaced my defective Epson R1800 with a new R1900. It prints beautifully. However, when printing from Photoshop CS4, after one image is printed and I attempt to print a second image, I get the following error message from Photoshop:

"Before you can perform printer-related tasks such as a page setup or printing a document, you need to install a printer."

Well, the printer is installed. I have just printed on it a minute earlier, and in "Printers and Faxes" in Control Panel the R1900 is listed and selected as the default.

If I close PS and reopen it, it will print one more image, but then the error comes up again.

Any suggestions would be helpful. Thanks.

More details: I can print the same image over and over, but when I open a second image, I get the error message. This has been discussed in the Adobe knowledge base, but their solutions don't seem to be much better than mine, which is to close PS and restart it, and then print that one image.

I think that PS saves the printer settings with the image.
Try this: Go to File > Page setup and set the R1900 there.