Wrong name of graph file from Das2

When I load a graph file from Das2, it sets extension as a human name instead of feature name provided by das2.

To reproduce
1) Go Arabidopsis thaliana, A_thaliana_Jun_2009
2) Then from Bioviz(Das2) server select AtTile1R > GSE9646 > 10h_ABA > GSM243689
3) Region In View, Refresh Data
4) Track shows name to be '.bar' instead of 'AtTile1R/GSE9646/10h_ABA/GSM243689'