(posted at 08:04AM GMT) 
I had the unfortunate experience of dealing with Tiscali Broadband support yesterday when attempting to resolve an issue with a potential new customers' Internet connection.
In short, they had zero routing to the Tiscali Retail network, had full routing to the Tiscali Wholesale network, couldn't see the BBC, couldn't see Google and had partial connectivity to various IPs on the Spilsby Internet Solutions network although not all of them - for example, they could see some of the secondary IPs on the shared webservers but not all of them.
A quick call to Tiscali Broadband support later and fast-forwarding through about four pages worth of troubleshooting; their 'engineer' (and I use that term as loosely as I possibly can) says that the static IP associated with this connection is 'corrupt' and they will have to delete and re-add the static IP.
(it isn't possible to have a 'corrupt' IP, but it is possible to have corrupt routing tables; which may have explained some of the problems I saw but not all of them)
The 'engineer' said that he didn't have access to the tool to do this until 5pm that same day - I called at 12pm - so, does five hours sound like a pro-active response time to you ?
Apparently, they have to contact BT for them to do this and at that point, I hung the phone up on him; total and utter bullsh*t as even the smaller DSL providers like Spilsby Internet Solutions have full control over what attributes (such as static IP/netblocks) are applied to their customers' DSL sessions - and it takes seconds, not hours to do! | 
