I just tried reserving bike places for my next trip using the Hull Trains website. I am being given an ambiguous and unhelpful message that leaves me wondering whether to proceed. I THINK that it is telling me that some of the trains both ways do not allow reservations, but reading it differently makes me wonder whether the Virgin train bike places are all booked up. I can 'proceed without bike reservations' if I like (which I don't like!) so I think that I will walk down to our local station tomorrow and get the staff there to sort it out for me.
edit - just seen your last post! yes I think this is the issue.
It wasn't a trip involving main line and local trains was it?
If so it will most likely tell you that local train bike bookings cannot be made. As essentially, with Northern, you don't need them. You do of course need a booking for the main line bit. They just have a cack handed way of telling you this. Similarly, while, on a cheapo ticket, the time of the train you can use on the mainline bit will be specified, in practice it is my understanding that the local bit of the trip will not be time specified. On the booking that bit will usually just be a suggestion so that you make the connection. If heading from northern parts back to London I often take an earlier local train to avoid problems caused by delays.
However, such is the mess of the system now, if your local station is handy and helpful (my Lancashire one is) you may be best just doing a quick check online and then peddling down to the station to get the bits of paper in your hand - not handing over any cash until they have waved printed train ticket AND bike booking in front of you.
ah, progress