Just installed the DF B58 (a great aeroplane based on one circut at KSEA), however the process came with a couple of gotchas. The F1 wrapper's drop down list for credit card expiry date didn't work. After 10 minutes of frustration I found that pressing "2" caused the year to advance from 2004 and pressing "0" advanced the month from 01. Not good! Then, when I clicked on the purchase option, a blank window appeared with nothing apparently happening. More frustration, not sure what to do as I didn't want to start a duplicate purchasing procedure. Eventually I clicked on the blank window and fortunately the normal purchase process window came up. I have had the expiry date problem in the past with the F1 wrapper but not the other problem so what is generally regarded as stable purchasing procedure seems to have a few wrinkles.