I had this problem alot and I started putting Carmex in my nose at night. It doesn't smell very good, but it helped alot.
Thanks for your suggestion. I'll give it a go. It's driving me mad so anything is worth a try :-)
I have this alot, and mine is due to a lot of sinus problems. You probably have a small cut or tear inside the lining of your nose. If the nasal membranes are dry, it is really easy to create a cut or tear when you wipe or blow your nose.
Preventatively, you could take a small amount of vaseline daily inside your nose. It won't hurt you at all, and no one will know it is there.
To get rid of the current issue, take some neosporin on a Qtip, and put it on the sore. Just be careful not to "pick" the scab. When it becomes dry, it can come off and you have to start all over again.
Good luck.
also, try some Saline nasal spraay. It isn't habit forming, and keeps the membranes moist.