zzzz, (thats what I feel like doing right now

)
The dnet program can't buffer more than 500 packets (I think). Each packet can contain different amounts of work-units (anywhere from 1 to 32). by my calculations, a 1000 mhz duron would need 4500 work units to buffer 100 hours worth. This means that each packet would have to average 10 workunits. About the only way to do this is to request the largest packet size. To do this, open the configuration screen in the client and select option 2 and then option 12. Set the value to 33. This means request 2^33 key packets which equals 32 work units.
It is still possible to get smaller packets than this. So, if you had already done this, or if you did this and it didn't help, you need sneaky (get from Russ' link above). Sneaky will allow you to get more than 500 packets into your buff-in file.