Error loading GDEF / GSUB / GPOS table 28333

[Ryan Schmidt <pango-2008b ryandesign com>]

Hi. I'm the maintainer for pango in MacPorts, and a user has reported  
some problems to me that I don't know what to do with, so I'm coming  
to you for help. Here's the bug report:



http://trac.macosforge.org/projects/macports/ticket/15052



First issue:



(wireshark:24691): Pango-WARNING **: Error loading GDEF table 28333

(wireshark:24691): Pango-WARNING **: Error loading GSUB table 28333

(wireshark:24691): Pango-WARNING **: Error loading GPOS table 28333


I myself have seen this issue with graphviz, not wireshark:

http://graphviz.org/bugs/b1318.html

So I suspect a problem in pango or maybe cairo, not a problem in  
graphviz or wireshark. Though for me, I notice no problem with the  
pango/cairo output. Just the warning message of which I don't know  
what to make. I am using pango 1.20.2, cairo 1.6.4, glib 2.16.3 on  
Mac OS X 10.4.11. I've seen the issue on a Power Mac G4 with Xcode  
2.5 and a MacBook Pro with Xcode 2.4.1.



Second problem is this message:

(wireshark:24691): Pango-WARNING **: shaping failure, expect ugly  
output. shape-engine='BasicEngineFc', font='Lucida Grande 13',  
text='Initializing dissectors ...'


And apparently then no text appears (only boxes). And apparently  
downgrading from cairo 1.6.4 to 1.4.14 made the problem (one? both? I  
don't know) go away for the reporter, though at the time I  
experienced the above error message, I was using cairo 1.4.14 (1.6.x  
had not been released).



Does any of this give you any idea what might be wrong? Any other  
information I can give you to isolate it? Is pango the correct place  
to look for this problem or should I be contacting e.g. the cairo  
developers? Thanks for any thoughts you have on the matter.