As an experiment, I have compiled 1.8e on the revived 1994 box running AIX 3.2. The build is available on FTP.LSOFT.COM in the LISTSERV/beta-1.8e directory as AIX32.tar.Z. The only file that should be used from this build is lsv (or lsv.o). Note that this build does not include DB2 support. If the error does not occur with this build, it means that the problem is related to the change in development environment from AIX 3.2 to 4.3. Otherwise the first thing to check is limit/ulimit.
Eric