I have an Acer Aspire Timeline 3810T which uses the 64 bit version of the CULV chip that's dual core running at 1.4GHz.

I prefer using KDE 4.x and have been using Mandriva for quite some time.
When I first installed Mandriva I attempted many times to install the 64bit version but could not even get it to restart after install was complete. I then used the 32bit version that worked better but now I'm experiencing a lot of problems. It boots fine into KDE but then I'm unable to click on the start menu and if I get any desktop items open like OpenOffice Calc as soon as it opens the screen is scrolling through the cells without me pressing a key.

I've spent some time trying to fix it and like Mandriva a lot but was going to even try to wait it out until Mandriva 2010 but since I need this computer for work I had to give up on that.

Since I want a good KDE 4.x based distro OpenSUSE seemed like the obvious next choice. My concern: In the past I've heard that OpenSUSE is more for heavy duty computers and that it runs slower and is not as stable as a system like Mandriva. Since I've never tried it I don't know but before I make the chance and wipe Mandriva off of my system, what have people experienced on here using OpenSUSE on similar hardware.

Also, would I be able to use newer kernels like 2.6.30 or even KDE 4.3 with OpenSUSE?
Thanks for your help.

Opensuse has live cd with is also a install cd so you can try it before installing.
Opensuse is somewhat bloated that is correct , but it runs on my dual core Intell
Is it less unstable than mandriva I do not think so.
Sometimes it needs some tweaking before it works correctly .
But if you get it working correctly it delivers what it promise a good working OS
It is clear running it from is Cd is slower than when it is installed