The problem is that Subs is not smart enough to know that it contains only a derivative. Changing the variables will help as it will remove the need for Subs (substituting t-x -> y). Maybe it would be appropriate to file a bug report with this.
Concerning the latex printer, there is a fix currently waiting as a pull request. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
