Not 100% certain, but I had the same problem and seemed to get uPNP working by changing the config file to use CIDR numbers instead of a subnet mask. For my network the subnet is 255.255.255.128, so my CIDR is /25, and I changed the file to:
allow 1024-65535 10.101.10.1/25 1024-65535
deny 0-65535 0.0.0.0/0 0-65535
Afterward, the daemon appears to run normally. However, I cannot find the location of the file in NVRAM to make the change permanent - it would be possible to just put in script in your init.d or something to replace the entire config file with the corrected version though.