URGENT: Undefined Symbols Using XCode 2.5 on Mac OS X 10.5

[Keary Suska <hierophant(at)pcisys(dot)net>]

I ha a perfectly functioning libpq before I upgraded my computer but for
some reason I am now getting undefined symbol errors in libpq.a:

AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-secure.o) reference to undefined
_pthread_sigmask$UNIX2003
AirBase:0: _close$UNIX2003
AirBase:0: _fcntl$UNIX2003
AirBase:0: _fputs$UNIX2003
AirBase:0: _poll$UNIX2003
AirBase:0: _SSL_CTX_set_client_cert_cb
AirBase:0: _pthread_sigmask$UNIX2003
AirBase:0: _sigwait$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-connect.o) reference to undefined _close$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-connect.o) reference to undefined _fcntl$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-connect.o) reference to undefined _fputs$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(noblock.o) reference to undefined _fcntl$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-protocol3.o) reference to undefined
_close$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-misc.o) reference to undefined _close$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-misc.o) reference to undefined _poll$UNIX2003
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-secure.o) reference to undefined
_SSL_CTX_set_client_cert_cb
AirBase:0: 
/Developer/Xcode2.5/usr/bin/../libexec/gcc/i686-apple-darwin8/4.0.1/ld:
Undefined symbols:
AirBase:0: /Users/aksuska/Projects/FFSEmploy/AirBase
Project/AirBase/libpq.a(fe-secure.o) reference to undefined
_sigwait$UNIX2003

Some googling around seem to imply that the problem is due to my project
linking against the 10.4u SDK, while libpq is linked against 10.5.

I tried to recompile libpq against the 10.4u, but configure seems to insist
on using 10.5 regardless.

Please help--I have a mission-critical project that is now dead in the
water--at least unless I decide to use a different DB back-end...

Best,

Keary Suska
Esoteritech, Inc.
"Demystifying technology for your home or business"