The operation could not be completed

HI, 

I'm posting this for the second time in case it's been missed. 

I have a bit of heavy web page that include a Ajax an some other controls, where I'm copying those controls from one page to another other and everything was going fine.But now, when ever I try to save the changes to my page it pops up this error message "The operation could not be completed. Unspecified error" in VS 2005 but I don't get the error with VS 2008 express.So, what could be the problem?  

 

Thanks   
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