I'm finding that IGB is displaying GFF files differently via Quickload rather than 'Open file...' for exactly the same file, see below for example.
In black is the Quickload version and in blue is the same file loaded via the File menu. As you can see the QL version is only reporting single long version with no introns.
In fact neither is really what should be shown. There is only one gene model in this locus so there should only be one example, but IGB is displaying the 'mRNA', 'exon' and 'CDS' entries in the GFF file as separate tracks rather than just one.
The data is valid gff3 format, as far as I can tell, but if I change the file extension to .gff3 (from .gff) I get the brown track. Yuk!
I really want to be able to use IGB for generating paper figures, but at the moment it is not possible.