Hello,
Since i found no Bugtracker i report them here. Please no adviced like reset the software, since im a Softwaredeveloper myself with expierence in embeded devices on Linux i know what i can try 
Bug 1 : Loosing Bookmark
Wenn you play a Movie and use (accidently or not the prev next Button the Bookmark get lost.
With Bookmark i mean the Information where you stopped that Movie last time.
So There is no Question if you wanna proceed on the last Part
BTW: Its unusual and unwise to have Cancle as Default for that Question.
I tell you why. If you make “OK” (means proceed on the last Position) as Default and you hit it by accident nothing is lost.
YOu have to stop and load again and deny the Question (cost you 5 sek) and all is good.
But since cancle is defautl and accident push loose the last position on the Movie wich can be a real pain to get back there (at least 3 MInutes if you know the exact time where you left)
BUG 2: Youtube (2 maybe connect Bugs)
Some Youtube Videos break the Box instantly and you have to pull the Powercord - reproduceable with same Videos
Also, everytime you use Youtube and watch Networkvideos aftwards you have max 10 min watching Time. The Box overload (looks like CPU on 100 or i guess its the ram so the box has to start to swap and if it cant kernel panic)
evreyting slows down and you have to turn it off
My Guess its the flashplayer - i guess you dont use Adobes since your Firmware is GPL might be legal Problem
If you use the GPL Flashplayer this might be the issue - anyway i think its a memory leak or something like that (sorry i dont start to debug now
Suggestions, i post it here since they are small and not mayor discussable things - just for useability
Suggestion1:
Make a Manual load Firmware from USB.
You have to edit the Textfile to fake a higher Firmware to downgrade it. Also a download Archiv for all Firmwares or at least the last 2 or 3) would help a lot to find issues
Suggestion2: make a dot in the Keyboard menĂĽ (default) instead of hiding it in the special characser keyboard menue
Suggestion3: prefilling networkmask / gateway and DNS when using manual IP
doenst hurt anyone and since the most homeuser networks are class c a prefilled class is will do the job
also prefill then gateway and DNS will be for most homeusers good enough - i know i know i could do a dhcp first and afterwards manuall and all is prefilled … anyway i dont think prefilling is a big efford.
Suggestion4: in youtube assigne the Search Button on the Remote to Search in YOutube.
also a possibility to prefill with a already typed search might be helpfull
for example : you make a typo and hit search now you wanna go back and correct the typo - not possible youfe to retype
Suggestion5: Manually add a NetworkShare - if network discovery doesnt work for some reason would be nice if you can enter hostname or IP to connect to a host
also a Small Ping to host application cuold help a lot of users
those things can narow problem easier down (had yesterday an issue - could connect to the WD Box by samba but it could not connect the other way - nothing helped (even hard and soft reset / firmware down and reupgrade nothing)
turns out i had to reboot my router which is weired since the connect to the box worked and the box had connect to youtube too) all this happened after BUG1 wherea youtube video crashed the box and i have to unplug the power
really strange sometimes
