IRC ip to decimal returning negative number

[13:23] -eotlbbs.synchro.net- *** RemoteClient -- NICK craowiest ~blauvp@192.252.211.197 frugalbb.synchro.net -1057172539 :duening

192.252.211.197 should return 3237794757

[12:59] -eotlbbs.synchro.net- *** RemoteClient -- NICK cruukest ~greawinge@199.229.254.129 frugalbb.synchro.net -941228415 :truuped

199.229.254.129 should return 3353738881