Increased RAM: Bios Setup System Dialog

I increased the RAM on my Compaq Presario SR2002X from 512M to 2G (both old and new are the same speed, PC2-4200). Both the BIOS Setup and the System dialog in the Control Panel show that they are using the new memory. As expected, a variety of things run faster now. In particular, all those security dialogs that come up and dim the desktop whenever you start some system maintenance process. They used to be slow to appear, but now they pop up almost immediately. Some programs start faster now -- the MSDN library displays almost immediately now, and it used to take about 30 seconds to initialize.

The surprise is that some things run slower. One thing that is particularly noticeable often occurs when entering text into a web page input area. With each keystroke, I can see the caret moving across the white background, but no characters appear. Sometimes I'll type in five or six keystrokes before it gets around to painting the characters behind the cursor. Another occurs with crossword puzzles displayed in Flash objects, such as the one in the daily L.A. Times. For these crossword puzzles, first you have to poke a puzzle-selection button; then it pops up a dialog with a choice of "regular" or "master" skill level. The pop-up used to display instantly; now there's a delay of about three seconds. Why would some things run slower after an increase in RAM??