First off let me say that I'm not very experienced with MS SQL.
We have a server that is running Server 2003 R2 Standard and has MS SQL Server 2005 express. SQL has been running well for a month or so but now is using a large amount of memory (up to 1.7 GB) and is sometimes using 50-99% of the CPU. The server has 2 GB memory and is running on a dual core opteron. If I restart the SQL service for the database, the memory usage will drop but gets up to over 1.5 GB in about a day. I first noticed it today because the SQL database was not working. If anyone has some input or suggestions about troubleshooting I would greatly appreciate it.