maximum file descriptors not higher than 983

[Weiersmüller Mathias (KIPO 14)]

I am trying in vain to increase the number of file descriptors that web polygraph uses:

when starting polyctl, I get the following message:

== snip ====
000.01| FDs: 65535 out of 65535 FDs can be used; safeguard limit: 983
== snip ====

=> Why does the safeguard limit stay at such a low level?

Additional information here:
============================
Limits:
-------
ulimit -n  =>  8192
ulimit -Hn => 65535
cat /proc/sys/fs/file-max => 205300

System information:
-------------------
OS: Ubuntu Linux, version: gutsy
Kernel: 2.6.22-14-server
g++ version: 4.1.3
CPU: Dual-Intel Xeon CPU 3.20GHz

polygraph information:
----------------------
version: 3.0.6
configured: with option: --without_ssl
=> when running ./configure, these might (?) be the interesting lines:
  checking for set_new_handler... no
  checking Default FD_SETSIZE value... 1024
  checking Maximum number of filedescriptors we can open... 65536


I am clueless. Are there other parameters to check/change?

Thanks in advance for a hint! 
BTW: web polygraph really rocks! Although I had a quick look on the application before, I just realized how powerful the whole suite is!

Regards

Mathias