Most likely you were hit by a bug in the Debian ports of the aolserver modules. The issue came up lately on the Aolserver mailing list for a different module [1].
In short: at least ion Ubuntu, the build system has added the default optimization flag "-Wl,--as-needed" lately. This optimization removes symbols which are not needed for linking. Therefore, the symbol Ns_DbDriverInit is probably removed this way, but is is necessary for the dynamic loading in Tcl.
To fix the issue, the Debian maintainer has to add "-Wl,--no-as-needed" to the CFLAGs in the Makefile before compiling. A bug report is filed for debian.
-gustaf neumann
[1] http://www.mail-archive.com/aolserver-talk@lists.sourceforge.net/msg00272.html
[2] http://stackoverflow.com/questions/14329967/missing-a-library-in-ldd-after-using-gcc-l
