I am not sure if anybody else has the similar issue, but for me am not able to see the attachment in the mail that I forward from my iPhone.
For example, I receive a mail with an attachment (lets say with .doc and/or .pdf with less than 1K) and when I forward that email to some other account by checking the option to include the attachment (iPhone will automatically ask you whether to include the attachment or not while forwarding), the mail arrives without any attachment to the mail content. I tried by sending it to different @yahoo and @gmail accounts and nothing shows up.
So, not sure how to tackle this issue. Man, sometimes I hate iPhone when it comes to few basic features.