Some light thrown on issues with memory leak in this kind of implementation in following articles(links).
http://www.eggheadcafe.com/articles/20021012.asp
http://www.aspnetpro.com/NewsletterArticle/2003/09/asp200309so_l/asp200309so_l.asp
http://www.codeproject.com/KB/office/fasterexcelaccesstoc.aspx
