Problems with Intel Dual Core processor

[Christian Schuerer <debian.lists@quincunx.at>]

Hello,

I've Debian testing/sid installed on a Sony notebook (VGN-SZ1M/B), which has a 
Intel T2300 dual core processor in it. I'm using the latest 2.6.17-kernel. 
Unfortunately, only one processor core is recognised. I had Kubuntu 
6.06/Dapper installed before (2.6.15-kernel), which recognised both processor 
cores.

Do I need to load any special modules? Shouldn't the kernel be SMP-capable? 
How can I get the 2nd core to work?

Thanks for your help in advance,

   Christian