Samsung TV wont connect to Laptop with VGA cable

Heres the situation:
LE32re87bdx Samsung TV
Connects to my vista PC fine, with a vga cable,

Using the same VGA cable, but connecting to my XP laptop (sony Vaio), the laptop display wont output onto the TV, and i cant select 'PC' option on the TV- the laptop doesnt recognise the TV is plugged into it, and vice versa.

its not a problem with the laptop though as when i connect it to a Tosh TV, the laptop display outputs fine on the TV

Therefore it seems to be an incompatibility with the Samsung TV and the XP laptop
is this common? am i doing something wrong?
there is nothing wrong with any of the hardware or the cables, as they all work, just the xp laptop and the samsung tv wont!