I'm experiencing a weird problem on StackPrinter hosted on Google App Engine.  
It seems that the application can't reach several endpoints like Super User or Server Fault; Stack Overflow and other endpoints still works.

This WORK (Stack Overflow)  
http://www.stackprinter.com/export?question=478760&format=HTML&service=stackoverflow&linktohome=false

This DOES NOT WORK (Super User)  
http://www.stackprinter.com/export?question=52483&format=HTML&service=superuser&linktohome=false

**WORKING sites list**:  
Stack Overflow  
English  
Meta Stack Overflow  
Programmers  
Ubuntu  
CSTheory  
Webmasters  
Photography  
OnStartups  
Statistical  
Wordpress  
Phisics  
Role Playing 
Tex  
Homebrew  
Unix  

**NOT WORKING sites list**:  
Gaming  
Apple  
Super User  
Server Fault    
Stack Apps  
Web Applications  
Ui  
Android  
Electronics and Robots  
Mathematics  
Cooking  
GIS  

It works on [StackPrinter mirror][1] hosted on Dreamhost; that indicates that it is probably a problem of connectivity from Google data centers to those particular domains/subdomains; looks weird though.

@Kevin, could you please verify if StackPrinter's calls reach SE server properly?  
This can be easily tested on [Top Printed][2] page.

Anyone suffering this problem?

**EDIT:**  
Follow this [post][3] on App Engine Google Groups.

**EDIT2:**   
Stackauth site does not work too

  [1]: http://stackprinter.systempuntoout.com
  [2]: http://www.stackprinter.com/topprinted
  [3]: http://groups.google.com/group/google-appengine/browse_thread/thread/8805770ab2191b50#