As I scan thru my log book, I am finding lots of these (dupe QSOs created during a LoTW import procedure), all seemingly from the 1995 CQ WW 160m SSB contest, where I made a big effort (over 1000 QSOs). Just noticed that the original loggings all have the exact frequency noted (note frequency, not band which is 160 in both cases) and the mode as LSB. The dupe QSOs, and there are at least a few dozen of them, don't have the frequency field filled in and are all listed as USB.
Perhaps this LSB vs. USB thing is the key? The imported QSOs are all noted as USB, which is of course wrong. And LoTW does not distinguish between USB and LSB, listing all SSB QSOs as simply SSB (is this an ADIF standard?). 73, Bill NT1Y
