two dimensional filter gadget: link to subset contains wrong filter

two dimensional filter gadget:
using in the greenhopper-field "Epic/Theme" as y-dimension and any other field as x-dimension.
Clicking on one of Epic/Theme items in any line results in opening the issue navigator with the following query:
project = PD AND labels = Approval
("Approval" beeing the clicked Epic/Theme). This results in "No matching issues found". IMHO the query should look like
project = PD AND "Epic/Theme" = Approval
which in fact finds the correct issues.