Pokewalker
How to Fix Pokewalker

I recently posted about Problems with the Pokewalker talking about small problems with the design of the Pokewalker. Unfortunately, It has a few unseen problems. I’ve received several reports of the Pokewalker or Nintendo DS game glitching and the device would no longer work. Thankfully, there is a solution.
If your Pokemon is on a stroll and you lose the Pokewalker or it glitches, you can retrieve your Pokemon. You can restore the Pokemon by going to the Pokewalker Connection Screen and press and hold: Up + Select + R. If you restore the Pokemon and it is still on your Pokewalker you will not be able to transfer it back (essentially making two of the same Pokemon).
Once you restore the Pokemon (or your Pokewalker has other issues) you will need to reset the back to it’s original settings. To reset your Pokewalker, go to your Pokewalker Connection Screen and hold: Down + X + L. This will sync the Pokewalker with your Pokemon game.
(via SereBii.net) Thanks Mat
Problems with the Pokewalker

Pokemon HeartGold and SoulSilver come with a Pokewalker, a small device allowing you to bring your Pokemon with you on walks. It can be used to level up your Pokemon, catch new Pokemon, or get more items. The small addition of the Pokewalker is bringing back old Pokemon fans who haven’t played the new games. But before you run off to pick up the remake of Gold and Silver, you might want to know the problems with the Pokewalker.
Level Cap
Each time you bring your Pokemon out on a walk, you can gain up to one level no matter how much you walk. For lower level Pokemon, it is much quicker to level them up in the game than it would be to use the Pokewalker.
Pokewalker Access Limited to Title Screen
If you want to transfer a Pokemon to or from your Pokewalker, you must enter the title screen (where you select to continue your game). This means if you are playing the game and are ready to save and go out with your Pokewalker, you need to restart the game and get back to the title screen before you can put any Pokemon in your walker. You can only transfer Pokemon from your PC to the Pokewalker so if you want to bring one from your party: you need to enter the game, find a PC, transfer to your PC, then exit back to your title screen to transfer them to your Pokewalker. › Continue reading
