Dashboard not available on subsite

Hi

I’m new to WP but am trying to learn. The situation is as follows.

I have WP installed on a local server
It’s installed in a subdirectory as I also have other apps installed (Gallery3/ownCloud)
It’s externally accessed by IP address
When the IP updates I lose the CSS and access to the Dashboard but can fix it by editing the MySQL database directly
The install seemed to take a while
The old site is functional but when I created a new subsite the new site doesn’t seem to pick up the CSS and I can’t get to the Dashboard. Of course I forgot to write down the error but it was along the lines of the address was not correct (it wasn’t a 404 – not found error)
I have checked the database for the subsite and the address entries seem correct.

I assume I’m using the latest version as I tried to update a week or so ago and it said it was up to date.

any help would be appreciated.

ta