[Citrix] GIMP doesn't see user's local drives

[tmanni]

I have no knowledge about Citrix virtualized environment and my Windows OS knowledge is limited.
IMO the issue is not related to gimp, because the open/save dialogs are standard dialogs provided by GTK+ framework (gimp only tweaks them to add file preview,  select only image files, ...) ; "Locations" available in these dialogs are GTK+ related.

Do you have the possibility to run any other GTK+ based applications ?