About one year ago, I used Slackware 10.0 on an IBM Thinkpad a21m, which model is now about 4 or 5 years old; I have never had this problem anyhow.
Actually, I own an HP pavilion zv5200 with a compiled kernel 2.6.12.5 and works like a charm.
A friend of mine used Slackware 9.0 and 10.0 on a Toshiba Satellite (something Celeron eeek) and another friend of mine uses Slackware 10 on a Sony Vaio, and we have never had this problem
I think the problem shall be your keyboard
Don't know for sure.
Good luck
Peace.