ltree gist index errors and fill factor questions

Hello,

We have an ltree column (tree_path) that has a gist index
(index_nodes_on_tree_path). This is in a 9.3.5 database. Recently errors
started occurring in the postgres log on some updates to this table:

fixing incomplete split in index "index_nodes_on_tree_path", block 2358

STATEMENT: UPDATE "nodes" SET "parent_id" = $1, "contents_id" =
$2, "contents_type" = $3, "trough_code" = $4, "live_flag" = $5, "ordering"
=$6, "id" = $7, "tree_path" = $8 WHERE "nodes"."id" = 127695

ERROR: failed to add item to index page in "index_nodes_on_tree_path"

Reindexing index_nodes_on_tree_path fixes the problem temporarily, but it
returns.

I'm wondering if this is a bug (googleing the incomplete split error
returns results about a similar bug with b-tree indexes) or a problem with
an inadequate fill factor setting. It doesnt look like there is a
specified fill factor for this index and I'm not sure what the gist default
is.

CREATE INDEX index_nodes_on_tree_path ON nodes USING gist (tree_path)

The table in question has about 94k rows, an example of the widest
tree_path tuple is 69066.69090.69091.69094

Any advice is appreciated, happy new year!

Mike