Dear Michael,
# This works
rtracklayer::import.bed('SRF.bed', genome = 'mm10') # this works
# But this doesn't
seqinfo1<- GenomeInfoDb::seqinfo(BSgenome.Mmusculus.UCSC.mm10::BSgenome.Mmusculus.UCSC.mm10)
rtracklayer::import.bed('SRF.bed', genome = seqinfo1)
# Neither does