HttpHandlers / Modules :: Global.asax 301 Redirect Fails On .HTM Files, But Works Fine Elsewhere?

I just bought an old domain name and am looking to redirect as many old URLs as possible to acquire backlinks intended for the original owner for pagerank reasons. The original site had a lot of static pages ending in .htm which need to be redirected to directories. I use httpcontext in my Global.asax file to initiate 301 redirects and this works great on folder names or .aspx files, but whenever I try to redirect a .htm it fails.

Sample code:

if (HttpContext.Current.Request.Url.ToString().ToLower().Contains("http://www.example.com/oldpage.htm"))
{
HttpContext.Current.Response.Status = "301 Moved Permanently";[code]....

I also tried using my Parallels H-Sphere interface provided by my hosting company to do a IIS redirect, but whenever I hit submit the page just starts an infinate loop of sending a request.