The following patch seemingly makes mod_mirrorbrain work with the old libaprutil:


--- mod_mirrorbrain.c   (revision 7798)
+++ mod_mirrorbrain.c   (working copy)
@@ -1127,7 +1127,7 @@
         const char *val = NULL;
         short col = 0; /* incremented for the column we are reading out */

-        rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, i);
+        rv = apr_dbd_get_row(dbd->driver, r->pool, res, &row, i-1);
         if (rv != 0) {
             ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
                       "[mod_mirrorbrain] Error looking up %s in database", filename);


I think we can quite easily change mod_mirrorbrain to work with both APR versions, 
either by detecting the APR version at build time, or by adding the patch to the Ubuntu
packages.

I don't know whether this fix works _well_, I can't really promise that at the 
moment, without looking into the database adapter (and its changelog) 
again.