WiShield 2.0 - Pachube feed freezes


I am able to upload data to pachube, but unfortunately the connection is not stable. After reset it stays alive for a few minutes and after that freezes.
WiShield v.2 is on a a Duemillanove and is WEP auth connected to a WRT54G running DD-WRT v.24. I suspect is something related to my router. Even when the feed freezes I can still ping the shield from inside my network.

Can you guys help with a suggestion on what might be wrong ?