Just re-installed PCLinuxOS 2011.6 KDE. I have Dell D620 Core Duo T2600 2.16 GHz 2.5 GB RAM. The laptop has 2 sets of 2 mouse buttons, above and below the touchpad.
I have a D620 also, a bit slower than yours and with less RAM, but I've found it to be a good steady machine running PCLinuxOS since about 2009.1. I presently run 2010.07 KDE with all updates to yesterday, and I field most of the other desktops (except GNOME full) on the machine for demo purposes. (Yeah, I upgraded the hard drive...
See if your upper buttons work differently with the J-stick (the "eraser head" pointing device in the center of the keyboard).
Mine seems to work like that: if I try to drag using the pad and the upper button, no go, but the J-stick (between G & H, actually) will drag just fine. This behavior may be by design. I hardly ever use the J-stick as it is very fast and hard to control for my thick fingers.
Most of the time I use my Logitech V220 wireless USB mouse. Much better feel and still very portable. A newer model, the M310 has the look and feel of the V220 but a micro-sized receiver that only sticks out of the USB port about 1/8" or so. Very much worth the $30 bucks or so.
Off-topic Question: how are you getting to 2.5 gigs of RAM? Do you have 3 GB installed and are sharing 512 Megs with a video card or something? (Do you have the Nvidia video card or the intel? Be aware that the Nvidia card has a history of overheating - keep your airflow path clean!)
The problem I am experiencing is that the top left mouse button does not work when attempting to do a click and drag actions. When I click within a text box the cursor is positioned where I click, but nothing occurs when I attempt to drag. The lower left button works as expected for this action.
Both sets of buttons work correctly for other actions as expected.
Yeah, I notice this on my Dell, too, just never considered it a problem as such.
Any assistance woould be much appreciated.
Well, at least I could confirm your symptom, and maybe add a bit more data. I'm definitely in the "use a mouse" camp here. It'll save your wrist in the long run.