Problem with TiVo connecting to TiVo service

[Publius]

I have a strange problem. I have two TiVos connected wirelessly to my home network. The one upstairs is working fine. The one downstairs can transfer TiVo shows from upstairs and access the internet, but it can't apparently download the latest program guide information from TiVo and has been unable to do so since Friday. It gives me an error code "N17". Does anyone know what is going on here?

On a separate note, this same TiVo got stuck on Saturday and had to be reset. Is this related?

Thanks in advance for your help,
Jamie