Says now playing but song won't start....bar stays at 00. What could be wrong?

either a mechanism problem---disc not turning etc or an electronic issue --someone would have to open the unit and insert a disc to see what is happening----also unlikely but possible the optical pickup that reads the discs is dirty or near failure---this will usually show up first on blu ray before a regular DVD.

go to the apple site and get help on there

Reset the player then try playing songs. Ensure that the battery is fully charged. You may also try formatting the player to reload musics. If the issue persists then get the player serviced.

acc or mp3 format i tunes can help maby just a ges

you can disable the sleep mode when you close the lid.

for windows xp

1. Click Start, and then click Control Panel.
2. Click Performance and Maintenance.
3. Click Power Options.
4. Click Advanced tab.
5. Under “Power buttons” section, select Do nothing from drop down menu for When I close the lid on my portable computer option.

for windows vista

1. Click on Start, go to Control Panel -> System and Maintenance -> Power Options.
2. Click on Change plan settings for the currently active plan.
3. Click on Change advanced power settings link.
4. In the “Power Options” dialog box’s “Advanced Settings” tab for the active power plan, expand Power buttons and lid.
5. Expand Lid close action.
6. Change the value to Do nothing for “Lid close action” by selecting a new option from drop down menu for both On battery and Plugged in.

The songs are in the wrong format, or their license has expired - there is nothing wrong with the player itself; use mp3 format songs only, and you won't have any problems

Start with these five simple solutions: Reset, retry, restart, reinstall, or restore
http://www.apple.com/support/ipod/five_rs/

If that all that didnt work, then i suggest you contact apple or your dealer for more assistance or repairs.

If you need more asistance, let me know. Good luck.

There can be a number of causes, if you are a Mac user and you don't use a clean eject app/script some of the hidden Apple cataloguing files can cause this issue. 
Songs in the wrong file format such as AAC or OGG can also cause this issue as can some firmware versions.
Start by making sure all the songs on the player are in a supported format, for most versions of this player that means MP3 and/or WMA, however this player has been released under several brand names in several markets and one or two versions don't support WMA.
Also, if you are a Mac user, use a clean eject app such as FinderCleaner, it's even supplied with an Automator workflow so you can create a menu item and/or folder action for it. 

I also had this problem and thought my music players were broken. The media players displayed the songs as 00:00:00 even when the file info read that it took up space and had a song length. The music player displayed that m506 error message.

I looked through forms for an answer, and I noticed I didn't try messing with one thing: THE BATTERY.

Try taking the battery out of your phone and putting it back in. It worked for me! My music players work again!

Make sure you back up all songs on the GoGear before attempting this solution.

1) Back up all files on the GoGear
2) Open up Philips Device Manager (Start --> All Programs --> Philips)
3) Click on the Repair Tab, and look for a msg that says connect the player while holding the volume + button
4) Disconnect the GoGear from the computer and turn the GoGear off - hold in the volume + button and continue to hold it as you reconnect the GoGear to the computer; after holding the volume + button for up to 20 or 30 seconds, a window will open up saying that your device is being repaired (now you can let go of the volume + button); after the repair is successfully complete, your GoGear will be good as new

Now you can do the firmware upgrade that will prevent this problem from occuring in the future. Open up Philips Device Manager and click the Update tab. This problem was caused because most GoGear's were designed for Windows XP with Media Player 10 (which is no longer the latest standard).

-Tha Mp3 Doctor