Odd actions by almost new HD1000 requiring constant rebooting

I have a new (about a month old) HD1000. Lately it's started acting 
oddly requiring me to reboot the system by unplugging it virtually 
every time I try to use it. Sometimes it fails completely to respond to 
any control input either from the remote or the front panel (with the 
exception of the on/off switch). Other times, it starts "looking for 
images" on my hard-drive (networked to my G5 Mac via a 10/100 Ether 
hardwire connection) and then stalls at 24 thousand and some files (it 
used to work perfectly). Today, I wanted to show a friend some pictures 
that I took with my Minolta Dimage 7Hi digital camera by inserting the 
flash-card from the camera (something that I have done successfully in 
the past). When I click on "slideshow", the Roku starts showing a 
folder full of slides from my hard disk which I looked at several days 
ago. It will randomly pick one of the images in this folder, and 
display it with a blue square bounding box superimposed over the image 
in the upper-left hand quadrant of the picture. This will stay up there 
until I hit the right arrow cursor control on the remote, then it goes 
back to the main display and highlights the "slide show" icon in the 
Compact Flash card field until I hit the arrow again, then it picks 
another of the old slide show images from my Mac and displays that, 
again, with the blue box on the screen. If I go back to the flash card 
and choose "browse" it brings up all the images, but it won't show the 
slide show. If I try to go to the hard disk I get a brief message 
telling me that the Roku is searching for files. It never used to do 
that before.

If I reboot the Roku by unplugging the power from mains for a few 
minutes and then plugging it back in and turning it on, eventually I 
can use it. But If I turn it off and then at some later date, turn it 
on to use it, it's screwed up again.

What gives?