[5x5]

This may actually be more of a Gmail issue, but they don't really have a good help section, so I'm giving this a shot here.
When I use Mac's Mail app, I can send and receive Gmail (and AOL) no problem, but when I try to use Gmail from the browser, it doesn't go to the recipient, but rather to the inbox in Mac Mail. It doesn't send (I've asked if they've received), and I have to forward it manually.
Now, this was a preexisting condition from before I saw the light and switched to Mac and would use Outlook, Outlook Express and/or Thunderbird on my PC.
So, is there a setting I forgot to change (on either end)? Does anyone else have this problem? It's really inconvenient to have to wait until I get home from work to send time-sensitive emails when I should be able to do it from the web. I know it works with my AOL account, but they're IMAP and not POP.
Any help would be great.
Thanks,
5x5