The Low Memory is most likely being caused by a Low System Resources problem.
IE: Too many things loading at Start Up.

See this link for a good description of ram vs resources.

http://www.aumha.org/a/resource.htm

And these links to help you reduce your startups.

http://www2.whidbey.net/djdenham/Index.htm

http://www.pcforrest.freeserve.co.uk/resources.htm

http://www.pacs-portal.co.uk/startup_content.htm