DVLA is being a pain in the ass ,,,,trying to tax my car online using either my log book details and reg or the ref off the reminder that i used to sorn it last month , bloody thing keeps telling me that the vehicle details are not recognised

Anyone had this before ,,hopeing its because im trying on the last day of the month or something ??
Btw i wasnt gonna tax it now and loos a month,s tax ,, just bored and having a look
