thanks for your email.

From what you have observed, it sounds much like the uninstall of 
the drivers has not been complete or the DMRantiClassic.kext is still 
loaded into the kernel in the system. You can check this with the 
System Profiler (choose its category Software / Extensions). There is 
no problem with any 10.4 version that I'd know of.

Remote Buddy will continue to be able to see that the Keyspan Express 
is connected to the system if the kernel module is loaded. Yet, since 
the kernel module already has exclusive access to this hardware and 
can only be unloaded with root priviledges, it has no chance to talk 
to the Keyspan Express IR receiver itself.

So, if the uninstall provided by Keyspan does not work as expected on 
your system, perform these steps to manually uninstall the software:

1) move KeyspanDMR.app to the trash and empty it 
2) remove DMRantiClassic.kext from /System/Library/Extensions 
3) reboot (to make sure DMRantiClassic.kext is no longer loaded in 
the kernel)

Please let me know, if this helps (it should) or does not help. If it 
does not, please check System Profiler for the DMRantiClassic.kext 
module.

Best regards, 
Felix