I traced the problem by analyzing the strace output of gimp.
After opening/parsing of what seems any single font configuration/description available on the system, gimp picks a font from /usr/share/fonts/type1/gsfonts. Apparently it is unable later to use this font properly. From an answer to a post on the gimp-users list, I understand that a limitation in pango exist, which will not properly/at all handle type1 fonts. After deinstallation of the package which provides this font (gsfonts and the dependent package gnumeric) gimp is back to normal. Final question: is this a bug in gimp? in pango? or should gsfonts be marked as colliding with gimp? Should I close this report?
