bt_fixroot: not valid old root page

Hi all,

I started getting these errors today on my test database (pg
7.2.1). I have been vacuum/reindex/analyze(ing) the table
all day (after updating 100000+ rows) and wondering what
could have caused this.

Thanks
Jim

2002-05-19 18:16:18 [1673] NOTICE:
bt_getroot[billed_features_btn_idx2]: fixing root page
2002-05-19 18:16:18 [1673] ERROR: bt_fixroot: not valid
old root page