I had re-installed dreamweaver, checked my system registry didnt find any errors but i still got the problem. After two bloody days i get a solution. If anyone face this type of odd problem you can try following steps:
1. If your DW running plz quit from DW.
2. Now find this folder:
C:\Documents and Settings\(username)\Application Data\ Macromedia\Dreamweaver8\Configuration\ WinFileCache-****.dat
(these folders are normally hidden – you should unhide them)
3. DeleteWinFileCache-****.dat. file
4. Restart DW.
Now enjoy your happy codding…..