Cant see printserver when using wireless, can when wired.

I have a problem where I can see my wireless printserver (from the
laptop if the laptop is plugged into the wireless router via ethernet.
I can not see the wireless printserver when the laptop is connected
to the wireless router via wireless. The printserver can be seen when
it is connected to the wireless router by both wireless and ethernet,
but again, only when the laptop is plugged in via ethernet. I have a
media center desktop that is connected to the router via wireless
also, which can't see the wireless printserver either.

Has anyone experienced this behavior before? What's wrong with this
setup?

The wireless router is: Linksys Wireless-B BEFW11S4
Wireless printserver is: Linksys Wireless-G WPS54GU2
Laptop Wireless is: Microsoft 802.11b/ Wi-Fi Wireless MN-520
Desktop Wireless is: Linksys Wirless-G PCI WMP54G