Transmission leak?

Hi there,
I'm brand new to the forum and have never owned a Mk1 before.
I have just put a deposit down for 1991 1.8 clipper, it looked really nice and seemed to drive pretty nice too. After I handed over the deposit I took another look under the car and saw there was a fair bit of oil around what I think is the transmission housing, around the seam. It looked like it had a couple of drips onto the ground within the half hour since the test drive.
It's a honey coloured oil and doesn't smell particularly strong- a little bit like burnt rubber though!
I couldn't really see any signs of a leak when looking under the bonnet.
Anyone know what it might be?
Is it a common occurance?
otherwise the car seemed quite nice and straight but I don't want to be buying myself into a problem from the start off.
It would be really appreciated if anyone has any views or advice. Many thanks.

Great! First post and I'm not getting the pics to appear, sorry!
Here's a link to photobucket I just set up.
Thanks.

http://s1383.photobucket.com/user/Trumanaut/library/?sort=3&page=1

Here are your pictures, can't help with the leak though.

Thanks for getting those up. Much appreciated.

Hi there I have had problems with a leaky gearbox and recently had it out and changed the drive flange seals which are about £8 per side . But I also had a similar leak to yours and this may or may not help but try tightening the bolts on the lower part of the box ,they should 13 ml . I only say this as I refurbished a box and painted it then noticed it was leaking through the bolts which somehow came loose. Cheap fix if it is .
Regards. Martin

if it doesnt smell its engien oil, probably sump or rocker gasket. gearbox oil smells really bad

Thanks guys.
I had a look but couldn't see what was going on so it got taken on a ramp and turns out it was the speedo cable O ring seal- there wasn't one! - gone or forgotten to replaced when the cable was replaced.
So problem solved, thanks again.