Murphy's Law struck about two hours later when I downloaded transactions into Quicken but they did not show up. I saw the transactions downloading, Quicken displayed the little flag indicating there were downloaded transactions to review, but the transactions window showed nothing. I just had to say, "hmmmm" as I closed and reopened Quicken. My ghost transactions then appeared.
Tonight I found out that if I downloaded the latest release of Quicken 2007, R3, (I did) this issue should be resolved. But -- if Quicken 2007 still has disappearing transaction downloads, Quicken is providing two zip files in the Quicken forum to remedy the problem. I downloaded and upzipped the files (didn't even need to open my WinZip) and then ran Quicken 2007, it started up much faster than it did before I applied the patches. Nice touch.