first i tried the sf version of the driver you mentioned, but nspostgres.so gave me the same trouble (i did change the reference in my nsd.tcl to nspostgres.so, and the log tells me that that's what it's loading, erm, *attempting* to load...)
then, out of a whim, i tried to compile the 7.2.4 sources of postgresql (for the fifth time) and what do you know? *all of a sudden* they compile! i have no idead what's happening here. perhaps my update to 10.2.5?
anyway, i still get the same error when starting up openacs, so i switched back to postgres.so (the one included in marks tarball) but still nothing but
[12/Apr/2003:11:34:13][509.-1610609172][-main-] Notice: modload: loading '/usr/local/aolserver/bin/postgres.so'
[12/Apr/2003:11:34:13][509.-1610609172][-main-] Fatal: modload: no such symbol '_ERR_get_error'
perhaps some header files are not right? my head? i'm close to giving up...