DHCP pc's can't talk to remote net, STATICS can,why ???? 1

[pbxphoneman]

computers I have in LAN A can talk to each other without a problem.Some are DHCP & others static.The ones that are static can talk to LAN A & LAN B (across a T1) and vis-versa ,it's just when I have DHCP computers (laptops) they can't talk across the T1...but they work fine in there own LAN A.If I give them a hard IP,works fine.Network is mostly win98se machines w/microsoft networks.
what am I leaving out? Something in my DHCP server /DSL router?? I never did define that network (LAN B) in the DSL router/DHCP server.Could that be a cause? The internet works ok in LAN A.

I'm taking small steps into intergrating the internet onto LAN B and wanted to just be able to get everyone talking between the 2 lans first before really screwin things up.My network diagram is here

http://www.citlink.net/~toddg/network/network.jpg

thanks a million

 

[jimbopalmer]

as a guess, the subnet mask assigned on the DHCP clients is not the same as the subnet mask you assign on the static clients.

A second theory would be that the default gateway you define statically is not the gateway the DHCP clients get.

Either way comparing a IPCONFIG /ALL should show the difference. I tried to remain child-like, all I acheived was childish.