query performance slow on 2.1.21 vs. 2.0.27

[Allan Streib <astreib@indiana.edu>]

Same directory data, same schema, same indexing.

Differences: 2.0.27/ldbm backend vs. 2.1.21 bdb backend

Performance on 4000 identical searches is four times slower on the 2.1.21 
slapd.

db_stat -m is showing 100% pages found in cache.

I've read some posts that suggest that 2.1.22 had some performance 
improvements, so I'll probably try that.  Other ideas?

Allan