[Neos] No backend "frontend" access anymore

[Adrian Föder]

Hi folks,
after upgrading to latest master again, I suddenly am unable to browse a 
frontend node in backend mode, i.e. e.g. 
http://dev.internal.edsh.de/flugplatz/anflug@user-adrian.html
I get a 404, but actually the log says,

 >>
13-04-21 12:42:23  DEBUG     Neos 
TYPO3\Neos\Service\NodeService failed to retrieve a node for path 
"flugplatz/anflug at user-adrian" with message: No workspace found for 
request path "flugplatz/anflug at user-adrian"
13-04-21 12:42:23  DEBUG     Flow                 Router route(): No 
route matched the route path "flugplatz/anflug at user-adrian.html".
13-04-21 12:42:23  DEBUG                          No CSRF required, safe 
request
13-04-21 12:42:23  CRITICAL  Flow                 Uncaught exception 
#1303209195 in line 75 of 
C:\Users\afoeder\PhpstormProjects\Edsh\edsh.de\Data\Temporary\Development\Cache\Code\Flow_Object_Classes\TYPO3_Flow_Mvc_Dispatcher.php: 
No controller could be resolved which would match your request. Package 
key: "", controller name: "Standard" - See also: 201304211242227a5766.txt
<<

Calling the page without the @-part works fine, however no backend 
"wrapper" is displayed then.

Any ideas what the problem could be here?

Thanks and best,

adrian