It seems challenge has exhausted the server...no WU available, even though gene/day is not very high. Maybe wu creator is down?

As I wrote on the BOINC @ TN thread on BOINC.Italy the 32 bit Linux executable was compiled on Ubuntu with kernel 3.2.0-56 and glib version 2.13, while the 64 bit was compiled on Ubuntu with kernel 3.2.0-23 and glib version 2.13..

I can't figure out why the 32 bit is resolved while the 64 bit still present the known issue related to the glib version.

Hope we can find out soon and solve this problem.
Thanks again for report here all the problems you guys found!

[...]-fno-builtin-function
Don't recognize built-in functions that do not begin with ‘__builtin_’ as prefix. See Other built-in functions provided by GCC, for details of the functions affected, including those which are not built-in functions when -ansi or -std options for strict ISO C conformance are used because they do not have an ISO standard meaning.

GCC normally generates special code to handle certain built-in functions more efficiently; for instance, calls to alloca may become single instructions which adjust the stack directly, and calls to memcpy may become inline copy loops. The resulting code is often both smaller and faster, but since the function calls no longer appear as such, you cannot set a breakpoint on those calls, nor can you change the behavior of the functions by linking with a different library. In addition, when a function is recognized as a built-in function, GCC may use information about that function to warn about problems with calls to that function, or to generate more efficient code, even if the resulting code still contains calls to that function. For example, warnings are given with -Wformat for bad calls to printf when printf is built in and strlen is known not to modify global memory.

With the -fno-builtin-function option only the built-in function function is disabled. function must not begin with ‘__builtin_’. If a function is named that is not built-in in this version of GCC, this option is ignored. There is no corresponding -fbuiltin-function option; if you wish to enable built-in functions selectively when using -fno-builtin or -ffreestanding, you may define macros such as:

#define abs(n) __builtin_abs ((n))
#define strcpy(d, s) __builtin_strcpy ((d), (s))
[...]

Version 4 have still this problem unsolved.
Interestingly, the 32bit version seem ok and the problem is only on the 64bit.

This problem is also present in the current debian stable 64bit as also reported in linux section of this forum.
So I don't think that a good solution is to say to partecipant: upgrade your system.
Try to get it fixed via static linking or using an older linux machine for compiling.