IBM TP 240X TYPE 2609-61A jumping cursor/keyboard problem?

[red_rolla]

Hi.

I have an IBM TP 240X TYPE 2609-61A. I noticed that sometimes when I start using the <Fn> + <arrow keys> combination to get the PgUp, PgDn, Home & End function.. a bit later when i hit the arrow keys and the "N" keys.. the cursor sometimes jumps around.

example in MSExcel, when it jumps.. it ends up randomly selecting cells in the spreadsheet. When browsing.. it sometimes clicks on links by itself.

has anyone experienced this problems? is it software or hardware? any hints/pointers will be highly appreciated!

thanks.