Bradford Student new member cannot set password - password token expired

[Juliehitgub]

Recently uploaded Bradford student has contacted me to say he cannot follow link from our welcome email. When he tries to set his password for first time it reads:
Reset password token has expired, please request a new one (see below)

Does this refer to our student coupon BRADFORD2015?

We have more Bradford students to upload as soon as possible.

[Floppy]

This should be resolved by #629. Password links were expiring after 6 hours, because originally they were only intended for resets, but now we use them for this, and people take longer than 6 hours to sign up.