Default [Q] Help with stock 2.1

Guys,

I am extremely sorry i am asking the same clichéd question again...

I read about this in many places, but i did not get an easy way, and hence i am asking....

i am currently on stock 2.1 update1 as it shows...

I have my galaxy s i9000 rooted....

Now, please please please could someone tell me if it is safe to flash cm7 directly on to my rooted and stock 2.1?

If not, please could you tell me what to do?

I am really confused...thanks and cheers