WD MyBookLive not connecting to new Linksys router

I didn't seem to find a thread directly related to this issue. I got a new wireless router, a Linksys EA2700. My old router was five years old and my WD MyBookLive hard drive worked fine with it. The new router works great however a window popped up on my iMac saying Time Machine hadn't been able to backup for two weeks. The hard drive is connected with an ethernet cable to the router. I'm still using OS 10.5.8. Should I remove the hard drive from my machine and reinstall? The Linksys help line folks weren't any help, after an hour they gave up on me. Same with the WD folks. Thanks for any thoughts.