Can't install Styles in D7: Precise error message inside this message (resolved)

Resolution (original post below): I had downloaded the development version thinking it would be much more up to date -- October vs early Spring. Instead it's just broken. That was the problem. Nuking it an replacing it with the "recommended" version worked. (I did have to manually delete the cache_styles table again, though, before the new (i.e., old) version would properly install. Alas.

Hi Folks,

I've searched but do not come up with an explanation. I'm running a pretty new, pretty clean D7 install. I wanted to load the media modules, which require Styles. The problem is, I can't load Styles. Whenever I try, I get an error which seems to suggest that a database object already exists, particularly a table called cache_styles.

EDIT: There is a cache_styles table in my MySQL database, along with a bunch of other cache_* tables.

Here's the exact error message:
DatabaseSchemaObjectExistsException: Table cache_styles already exists. in DatabaseSchema->createTable() (line 621 of /var/www/drupal7/includes/database/schema.inc).

Okay, so I went to phpmyadmin and dropped the cache_styles table and tried again. This time I got this error:

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1072 Key column 'label' doesn't exist in table: CREATE TABLE {styles} ( `sid` INT unsigned NOT NULL auto_increment COMMENT 'The primary identifier for a style.', `field_type` VARCHAR(128) NOT NULL COMMENT 'The field type.', `name` VARCHAR(255) NOT NULL COMMENT 'The style name.', `description` LONGTEXT NOT NULL COMMENT 'The style description.', PRIMARY KEY (`sid`), INDEX `field_type` (`field_type`), INDEX `name` (`name`), INDEX `label` (`label`) ) ENGINE = InnoDB DEFAULT CHARACTER SET utf8 COMMENT 'Stores configuration options for styles.'; Array ( ) in db_create_table() (line 2595 of /var/www/drupal7/includes/database/database.inc).

It looks to me that the code to create the styles table is trying to add an index on a field that's not defined.

I'm blocked. If you know what's going on here, or want more details, please let me know.

Kevin