Clive Strong notes that transaction names in SQL Server are case sensitive:
I had an issue today running a colleague’s code (the rollback and commit were commented out, but that is another story). The code failed and I tried to rollback the transaction but received this error message;
Msg 6401, Level 16, State 1, Line 5
Cannot roll back t1. No transaction or savepoint of that name was found.
I can’t remember the last time I named a transaction, but if you are in that habit, it’s important to remember.