You used to be able to send and receive SMS from ICQ, this was a very useful feature - sending was free (and still is), you have a proper keyboard to type on, and my friends without cellphones have ICQ.

ICQ has upgraded their system so that the SMS phone number is the ICQ number with a 3 digit suffix (481 I think), which is very cool but it looks like they've switched their SMS provider to do it. Now we can receive SMS from ICQ but if you try to reply it says invalid number, apparently the send/recieve functionality is still there though so I'm assuming this is a Vodafone<->ICQ's Telco issue?

Infact right now (today) you can't even send with ICQ, but I'm presuming/hoping that that's just a temporary thing.

Does anybody know what the story is?
Is vodafone even aware that a lot of people would like this working?
Any advice on who I should contact about this?

Not being able to recieve SMS from any internet connected service or application was one of the reasons telecom mobiles were a joke around here - it was a good reason to use vodafone, but one of the most used applications has just lost half its functionality.