NAS problem with Vista

[flwolf]

I have two ethernet hard drives connected to my Linksys router. One is a Western Digital Netcenter and it works perfectly fine. The other is a Mapower Landisk and I'm having trouble with it. Vista sees the drive, but when I try to access the drive it takes FOREVER to show the contents of the disk. The green "searching bar" never completes and Windows Explorer eventually hangs. Any ideas?

Edit: Both drives work perfectly fine with XP.