Running the boinc client produces the following output, which scrolld continuously and has to be stopped manually:

2008-05-23 09:56:30 [---] Starting BOINC client version 5.4.11 for i686-pc-linux-gnu
2008-05-23 09:56:30 [---] libcurl/7.15.4 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.3
2008-05-23 09:56:30 [---] Data directory: /home/dave
2008-05-23 09:56:30 [---] Processor: 2 GenuineIntel Intel(R) Core(TM)2 CPU 4300 @ 1.80GHz
2008-05-23 09:56:30 [---] Memory: 1.92 GB physical, 4.00 GB virtual
2008-05-23 09:56:30 [---] Disk: 173.51 GB total, 164.32 GB free
2008-05-23 09:56:30 [---] No general preferences found - using BOINC defaults
2008-05-23 09:56:30 [---] Local control only allowed
2008-05-23 09:56:30 [---] GUI RPC bind failed: -1
2008-05-23 09:56:30 [---] GUI RPC bind failed: -1
2008-05-23 09:56:31 [---] Local control only allowed
2008-05-23 09:56:31 [---] GUI RPC bind failed: -1
2008-05-23 09:56:31 [---] GUI RPC bind failed: -1
2008-05-23 09:56:32 [---] Local control only allowed
2008-05-23 09:56:32 [---] GUI RPC bind failed: -1
2008-05-23 09:56:32 [---] GUI RPC bind failed: -1
2008-05-23 09:56:33 [---] Local control only allowed
2008-05-23 09:56:33 [---] GUI RPC bind failed: -1
2008-05-23 09:56:33 [---] GUI RPC bind failed: -1
2008-05-23 09:56:34 [---] Local control only allowed
2008-05-23 09:56:34 [---] GUI RPC bind failed: -1
2008-05-23 09:56:34 [---] GUI RPC bind failed: -1

System is Guadalinex 4.2 (distributed by the Government of Andalucia, Spain), based on Ubuntu Edgy (6.10), but with Feisty 7.4 kernel. Package downloaded and installed using synaptic package manager.

Unfortunately, there are a number of reasons why this error could show up. I'm not familiar with the distribution you're using, so I can only give a high-level approach.

Basically, the error shown means that BOINC could not open a socket (network) connection on your Linux machine (for the GUI to talk to the daemon). Most likely, this is a permissions issue. If you run BOINC as root, does it work? If so, that confirms a permissions problem. Another issue could be trouble with your network card, such as networking not being initialized , a bad configuration, or a very strict firewall turned on. These are all things to check.

Eventualy a problem by resolving the hostname and localhost. What did "nslookup localhost" and ping localhost say ?
Does it work, if you start the BOINC client with "./boinc_client -no_gui_rpc" ?

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