yahoo small business permalink problem

i’m using yahoo small business to host my website.

i am trying desperately to remove the ‘index,php’ from this permalink format:
/index.php/%year%/%monthnum%/%day%/%postname%/

but the permalinks simply won’t work unless the index.php is specified.

i have wordpress stored in
domain.com/wordpress

and the blog URI itself is in a subdomain
blog.domain.com

i would love to just hack the .htaccess, but yahoo’s support pages say that .htaccess is not available.

is there a fix i can perform or is this an issue with Yahoo?

i know that yahoo designed a plug in, but i am started to suspect that the plugin is not robust enough to support subdomains.

can anyone verify this?

thank you!
t