Different results on different servers

Hi there,
I was wondering if anyone could tell me why when i use a different server I get F’s for First byte time, Compress text and images.

I can understand the first byte time but why does the server make a difference to text compression, I havent applied any compression but when i done the test on my Linux Dedicated server it worked fine.

Thanks
Jack

Give us some links to the different test runs. Otherwise hard to tell.