Mapping drives on NT 4.0

Hi. I have 3 network drives from my NT server mapped to drive letters on my
desktop. They are F:, G:, and H:. I have these drives set up to re-map on
login. However, the drive mappings seem to be multiplying. Now I:, J:, K:,
L:, and so on toZ: are all mapped to one of the 3 network drives. Has
anyone ever seen this problem before? Might someone be able to provide me
with a solution? Thanks!