I have purchases 'pending' since before Christmas and some that never showed up at all
Nothing has converted into actual miles.
I know some of you guys probably won't like hearing this, but the equivalent BA scheme, which came along a couple of weeks after the bmi one, is working perfectly. All my purchases showed up quickly and all have converted into actual BA miles. Having just checked, all my Christmas purchases credited as actual miles on 11 Jan and January sales purchases had all credited by the end of that month ^
This is a poor show from bmi, especially when such a direct comparison is available. If a retailer is covered by both schemes, I now automatically choose BA, even though the bmi miles/£ rate is usually better.