You should be getting 10p per word for articles, and £60 per page for photos. In the past they used to be pretty open about rates, nowadays more and more stuff is getting haggled over as budgets are tight, eg reviews in return for the gear. Not unusual to not get paid for extended captions up to ~500 words, get paid months later, or not get paid at all. At least they can't lose your slides any more. As both Uk mags are now run by photographers, your shots will have to compete with their files.
Not all bad though - if you can put a good feature together - say six pages, 2000 words plus pics, it should earn £400+. If you bag the cover too that's another £150ish.