[WordPress theme, embedded] intermediate image sizes

I posted this over at the WPG2 forums too, but I'm starting to think it's really a Gallery2 theme issue.

The theme for Gallery2 I'm using is designed to work with WordPress to look best in embedded mode. Here's my embedded gallery page in my WordPress.

This theme has a default intermediate image size of of 640x480. Due to layout problems on my embedded page, I'd like to shrink the intermediate size down to 50-75%.

I believe this is under the Edit Album tab, "Resized Images" section. Right below that is the "Recreate thumbnails and resizes" section with a "Recreate resized images" option. I tried this but now all the image pages (../ac_power_tester/IMG_2540.jpg.html) are broken.

Have I screwed my G2 database? I also tried regenerating the thumbs and resized images but it stopped at 155 out of 1000.

My sys info:

Gallery version = 2.0.2 core 1.0.0.2
PHP version = 4.3.11 apache
Webserver = Apache/1.3.33 (Unix) mod_auth_passthrough/1.8 mod_log_bytes/1.2 mod_bwlimited/1.4 PHP/4.3.11 FrontPage/5.0.2.2635 mod_ssl/2.8.22 OpenSSL/0.9.7a
Database = mysql 4.0.25-standard
Toolkits = ArchiveUpload, Exif, ImageMagick, NetPBM, SquareThumb, Thumbnail, Gd
Operating system = Linux bigjohn.wetopthemall.net 2.4.21-32.0.1.ELsmp #1 SMP Tue May 17 17:52:23 EDT 2005 i686
Browser = Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/417.9 (KHTML, like Gecko) Safari/417.8