SQL 2005 Express - Sqlserv.exe Memory Usage Always Increasing.

Hi,

I'm hoping that some might have an answer for me after much net searching.

I have a server (200GB disk space, Dual 3.8 GHZ processors, 4GB memory) that hosts 6, very small, SharePoint sites (WSS 2.0) and SQL 2005 express handling 1 config DB and 7 content DB's.
The biggest DB at the moment is only 300 MB and the sites are not actively being used yet, they are only open to a select number of users (+ - 25 in total) who are using them as reference "areas" at the moment. Each site is running in it's own application pool as well.

I find that the sqlserv.exe process increases in memory usage and does not seem to decrease. It gets to the point of 960 MB usage and then databases cannot be used (SQL 2005 Express max memory is 1GB). SQL seems to "close" them down and site errors being received are "site is not in configuration database". When the SQL service is restarted the memory usage idles around 70 - 80 MB, the sites are 100% again but after an hour or 2 the memory usage is sitting at 560 MB again and doesn't seem to decrease.

Is there a way I can bring this memory usage down?

Any feedback would be greatly appreciated.