Custom Permalinks cause 404 Error on some Pages

Hello,

I just created my first blog using version 3.0.1 on IIS 7 Windows Server 2008.

Anything other than “default” in the Permalink settings causes 404 errors on two out of four of the pages on the blog. I have scrutinised the settings on these pages and they seem to be identical.

I have tried various suggestions on this forum including deactivating plugins, playing with the general settings, particular custom structures and “almost Pretty Permalinks” but I still get the 404 errors. None of the other posts I read describe a partial problem like mine, it seems to be all or nothing.

When I change the settings I get the “structure updated” message so does that mean I have an httaccess file and that it is writeable. I don’t find this file. Where is supposed to be?

I would so appreciate any suggestions. The site is at http://www.funenglishexercises.com in case this helps but at the moment the settings are default so the pages show up.

Thank you in advance.

Deborah

p.s. I hope this post doesn’t appear twice – I somehow lost the first one.