Dell Inspiron 1525 Keyboard Problem

I have an Inspiron 1525 laptop that I have recently replaced the hard drive and RAM in but am now having some issues with the keyboard. I have looked all over the place and cant seem to find a solution for this. Here is the problem, when I am typing, the "U" key and the "O" key act as arrow keys and so do the other keys that have the number on them. If I hold down the Fn key, they act normal and when I use the NUM lock, it inputs numbers. Has anyone ran into a similar problem or have a solution for this? Thank you in advance!