Ok, it's official. I am indeed a moron! :P
It was the templates - main, select etc. Ya see I opened them in CoffeCupFTP's window and pasted them into the template like that. But the first one I'd opened was the 'redirect' and that was only one line, so when I opened the others I could only see up to the header - there was a lot of space before the tables. Never occured to me to scroll down to see if there was anymore to it. Everytime it called the weather_main or weather_select, there was only the headers there. Duh! I've just pasted the full versions in there and everything looks gorgeous and works perfectly.
So thank you for this, I'm thrilled with it. And next time somebody complains that something doesn't work and you have no idea why, bear in mind they have probably missed the blindingly obvious.
Oh and the fella who wants it on his VBIndex page.....I can't tell you how to get it in the blocks, that's beyond me, but I got a template that'll fit your portal. It works on VBPLite, so should work on yours. Look at my
portal and you'll see it blends in. I've left out the humidity and barometer stuff, they can get that from the detailed forecast, but it's easy enough to add in. The template is aligned to the right, but all you'd have to do is align it to the left if you prefer that. If you want the table as it is on the original hack, that'll work too - you'd just put the variable before the centre blocks load. I think.
As the man said, put your code on the page that calls VBIndex. I've put it on the vbplite.php (which I'd renamed to portal). It goes in the same place as you'd put it in the index.php - before it called your portal page. Mine is called 'P_home'. Dunno what VBIndex calls them, but just put it before it calls that template. Then put the $currentweather variable after the 'start themeleftcolumn' or 'rightcolumn' (or vbindex equivalent) in that template and it'll put it there. Should imagine if you want the original box with the hack, you'd put it before or after the centre block. Trial and error mate! If I could figure it out - and hey idiot here! - then you will. Persevere!