Stretching and dragging windows

Windows 7 (or maybe my new laptop?) is giving me lots of trouble when I try to stretch a window. There are two problems:

1 - Sometimes when I grab an edge I end up moving the whole window. I believe in earlier Windows versions you had to click on the top section of the window to drag it. Grabbing an edge always resulted in stretching. What is the magic touch that distinguishes grabbing to stretch from grabbing to move?

2 - Often I can't grab the edge at all. I hover over it and get the familiar two-ended arrow, but when I click, it just goes away... back to the regular mouse pointer icon. What is the magic touch to actually grab the edge once you get the two headed arrow?

TIA
LAS

You still have to grab the top to move, unless you use the keyboard. But Windows 7 has many ways to move or resize a window. I assume you know about Aero Snap.

As for the double arrow problem, it sounds like the position of the cursor does not agree exactly with the edge of the window. Maybe try moving the cursor slightly left or right to get the double arrow to stay available. I don't know what settings you have for your mouse, but you could check. I suppose if you can't get it to work as you wish, you might think about another mouse.

Just for our information, what resolution are you running?

"You still have to grab the top to move, unless you use the keyboard"
Apparently I wasn't clear. You describe my experience in XP, but in Windows 7, I find myself moving the window when I wanted to stretch it instead. That is, I can move the window by grabbing it on either side and the bottom, not just the top. I view this as a bug, not a feature. It makes it hard to stretch the window. If I try and try again, I can get it to stretch. My question is, what subtle thing makes it move instead of stretch? Is no one else having this experience in Windows 7?

As for your suggestions about the double arrow problem, does no one else have this problem? I do what you suggest, wiggle the pointer until I finally get the behavior I want. I have tried various resolutions and Personalize/Display settings and the behavior is the same in all.

Again, I'd be interested to know if others have this problem. My mouse is a Logitech Trackball. But I've just now experimented and I have the same problem with the mouse pad on the laptop. It's a dell XPS L702X.

tia
las