NETBIOS - Dropped Internet Connection

[UncleAelfrich]

I have a small home office network ... 2 PCs and a laptop all running Windows XP Professional ... plus one Linux box serving as a file server/print server. The problem I have is that with the linux box connected to the network, the XP machines constantly drop connections. For example, while downloading a file, the XP machine will stop receiving packets from the web site where it was downloading. If we shut the linux file server down, then the XP machines do NOT drop the connections and are able to download large files, etc. without interruption.
I also run Kerio Firewall on the XP machines, and what I notice when the linux file server is running is that the XP machine will receive a netbios-dgm request, and it is after that request that the connection to the web site is dropped.
Does anyone have an idea as to what may be causing this problem?

[UncleAelfrich]

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