Find out about Tiscali here ISP's known to BLOCK or Filter p2p or specifically Limewire. Tiscali is spread around Europe. Not all of their branches use exactly the same techniques.

If I get zero speeds, LW appears to have paused, I will re-search them, if they don't restart downlding, then cancel & reselect from search results. If that doesn't work, then I would close LW, re-open 10 mins later hoping to get a different set of Ultrapeers (UP) to connect thru. There are some DUD UP's out there. But yes it does sound like your ISP is at fault. And no they won't tell you about their shaping of p2p bandwidth. In fact, most people who work there probably wouldn't even know about it.