zsh spinning for ages when I hit tab on directory

[Markus Trippelsdorf <markus@trippelsdorf.de>]

Zsh is busy spinning for minutes when I hit tab at the end of an
directory. For example consider:
~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
man1 % l
total 1748
drwxr-xr-x 2 root     72 Nov  8 13:37 .
drwxr-xr-x 4 root     28 May 27 15:33 ..
-rw-r--r-- 1 root  42888 Nov  8 13:37 cpp.1
-rw-r--r-- 1 root 824844 Nov  8 13:37 g++.1
-rw-r--r-- 1 root 824844 Nov  8 13:37 gcc.1
-rw-r--r-- 1 root  24554 Nov  8 13:37 gcov.1

When position the cursor after the man1/ of 
~ % /usr/share/gcc-data/x86_64-pc-linux-gnu/4.7.0/man/man1/
and hit tab, zsh starts spinning:

 96.79%  libzsh-4.3.12.so   [.] 0x7185f
  0.12%  [kernel]           [k] handle_irq_event_percpu
  0.07%  libFLAC.so.8.2.0   [.] FLAC__bitreader_read_rice_signed_block  
...

And after a few minutes it prints:
---- no match for: `external command', `executable file or directory',
`builtin command', `shell function', `alias', `suffix alias', `reserved
word', `job', `parameter', or `corrections'

Any ideas how to fix this behavior?
Thanks.
-- 
Markus