After reading this thread I'm curious, what is the exact error you are encountering when trying to access your home ip from the work place?
From what you've said you can successfully access the web service from both inside and outside of your LAN, however the only place you have an issue is at work which suggests your port forwarding and local configuration are fine and the problem is something such as a proxy which is causing you trouble.
I often have trouble with the gateway at work - and in the case of my box will allow me to connect to web service but won't allow me to access other ports such as the admin login, I'm wondering if you're experiencing something similar or can you not access anything at all?
Q) how many mice does it take to screw in a light bulb?
A) just 2, but the problem is squeezing them in there.