Deadlock retry problem

The following code catch into deadlock.

When I doing retry - computer hung (retry with no success).

What may be the reason for that?

    while select forupdate salesLine index hint SalesLineIdx
           where salesLine.SalesId == this.SalesId()
    {
        try
        {
            ttsbegin;
  // do something
            ttscommit;
        }

        catch (Exception::Deadlock)
        {
            retry; // *** here the program stucked and not continue.
        }

        catch (Exception::Error)
        {
           throw error("error");
        }
    }

Thanks :)