mouse pointer problem in ubuntu9.1

[arunpkd]

hi i am new to ubuntu. yesterday i installed ubuntu 9.1 in my desktop as dual boot with win xp. the problem i am facing is in ubuntu there is no mouse pointer,instead there is a small square box filled with coloered pixels which acts as mouse pointer.
also when i shutdown the system a red screen with rows to white blocks appears.
please help me to solve my problem

[semi_fiction]

What computer and graphics card are you using?

[arunpkd]

amd athelon core duo, asus motherboard,
for graphics card i dont know exactly. pls tell me how to find out,
there is an icon in task bar in xp which says "s3"