[Gretl-users] Mysterious error with a simple subtraction

Hi, I've run into a strange error which I'm sure is a bug, at the very least because the error message is absolutely uninformative: <output> ? series tully = tul2an – tucpn Fehler bei Skriptausführung: Stopp </output> (Re-translated it just means "error while running script: stop".) As you can see the operation is a simple subtraction. The series tul2an and tucpn do exist, gretl happily displays their summaries just before that. The context is a pretty large panel dataset with lots of missings (but temporarily declaring the data as a large undated cross-section didn't change anything). The dataset is not yet subsampled at that stage. I've tried all kinds of variations with zeromiss() and misszero() but that didn't help. Unfortunately I cannot provide the (confidential) data. The version is now the latest snapshot in Win7 64bit, and it also happened with a snapshot from a month ago. Any ideas for workarounds, further things to try and test? Thanks, sven