[daip] FRING "feature"

[Ketan Desai]

unless the data has been regridded in frequency [which is unlikely]
this message is very likely harmless.  One key question though, are you trying
to fringe-fit across multiple IFs?  If so, your frequencies most likely do not
lie on a uniform grid across all IFs in a multiple IF fit. in that case,
its unlikely you can do much about it so either way, don't worry about it.
[though you might consider not fitting across multiple IFs - at low frequencies
the fit is a bit problematic due to the ionosphere]

if you have a different circumstance, it may be a bug - but that's unlikely.