I'm sorry, but did it strike anyone else as weird that Angelique could just lift the curse - presto! If it was so easy, why didn't she do it at some other time, like say in 1897 when she had to give Barnabas all those injections after Julia was ripped out of the past? Why didn't she just lift the curse then, if it was so easy - since she obviously was trying to help prevent his exposure as a vampire to the 1897 Collins family then as now (1840).
But Angelique has changed more in 1840 than she did in a more limited way in 1897. She wanted to help in 1897, but she may not have been willing to completely cure Barnabas at that time.