[nigel_b]

There's two things you need to check in the system settings then.

First, the datum should be OSGB36
Second, the position format should be "British Grid" or "OS Grid" however they have described it.

You shouldnt have trouble then, although if you're used to 6 figure grid references like

SY 386 425

then you'll have to get used to adding two extra digits like this:

SY 38673 42582


the 386 in the 6-digit grid ref. example above tells you how far across a 100,000m square you are, i.e 38,600m across it. The next increment 387 is 38,700m across it, 100m further. As GPS is much more accurate than 100m resolution, the extra 2 digits are added representing tens of metres and metres.

Let us know how you get on!