Desktop and handheld OS make NO difference on POP integration.
Like jibi said, POP accounts are polled every 15 mintues. If you get a message in your gmail account and the polling timer is at 14.5 minutes, then you only wait half a minute, but if it comes in and it was polled just 2 seconds ago, you are looking at a 15 minute wait.
You can double check the deleted items folder on your web account and make sure there is nothing huge being held in there. If you are running low on space and that's why the gmail forwarding isn't working anymore.
you can try disabling forwarding on gmail, then re-enable it.
LASTLY.... it took you 23 minutes to type that post?