file-roller complains that "tar" command not found

Very weird combination of events

- change PATH in .gnomerc
export PATH="$PATH:/something/else"

-in Nautilus, open (doubleclick or click) a tar.gz file. file-roller will open
if the filename is long (over 24 chars before the .tar.gz, may vary if more than
3 dots in name) or has more than 3 or 4 dots in it (depends on the filename
length) you get an error

/bin/sh: tar: command not found

opening the file normally (file->open in file-roller) or by DND works okay

tried to replace /bin/sh by a bash script of mine dumping $PATH, it turns out
that in some cases, PATH is not complete (just the 8 or 9 heading characters).
Likewise, tried to replace /usr/bin/file-roller by a bash script dumping PATH:
everything seems fine.