[Hampshire] Ubuntu installing problems

Hello everyone,
Well I am trying ubuntu for the first time (second really - I tried a
live boot CD before, and couldn't bear how orange it was - I am giving
it another chance ;-) ).
I downloaded a ISO image from the official ubuntu website - chrome was
playing up a bit with my downloads, so I switched to firefox, and after
that it downloaded OK.
I opened it with an application ubuntu reccomended called infra
recorder, and while one message came up (I can't remember what it was,
but it was more like information than and error message- nothing that
seemed too important), everything seemed to go OK, and it was done in
under a minute.
I placed the CD in my laptop, and chose boot from CD/DVD option, and
that came up OK.
Then I tried to 'Try ubuntu without installing it', and the message that
came up was something like 'I/O error - reboot'. I tried again, and the
same thing happened, so I then picked option 'check disc for defects',
and the same error message came up, as it did with 'install ubuntu'.

I have downloaded Mint from the official Mint site a little while ago,
and that also wouldn't load, but a lot of error messages came up whilst
I was burning it, so I thought that I had burned it wrong.

Now I am beginning to wonder if it's a problem with my laptop.... I have
promised myself I will NEVER get an Advent again.

Thanks,

Becky

PS I didn't know Alan Pope ran the ubuntu podcast! I checked it out
today, it's pretty cool! ;-)