Need Help Converting A CHAR Into A Datetime

I have a Database which is having a Counterdate time Column stored in the form of Char(24)

But i need it to be in form of datetime so that i can use the datetime functions on it..When i use the cast or convert inside the function where i am passing this character it gives me error

"Conversion failed when converting datetime from character string."

I am done all permutatiions and combinations for this used

Set @DE = convert ( datetime, @ts,121)

Set @de = cast( @ts as datetime)

BUT ALWZ give me same error.... also when i copy the whole of the data table into some other database the error doesnt come.. i converts the character into the datetime..

I DONT understand why the Server is behaving wiered..

Hoping to get an answer soon.

With regards

Sharad

Database Developer ,

UIC