Batch processing and missing variant

At this client we encountered a very strange problem and i can't find the cause of it. So maybe someone can give me some pointers to look at.

We have a batchjob that consists of 7 jobsteps. Each step is run with its own variant.The batchjob terminates at the end of step 2 with the message that the variant for step 2 is missing. And that's where it gets a but hocus pocus for me...

How can step 2 be executed with its variant only to be terminated at the end with the message that the variant is missing? And hence raising a system exception:

Message DB 612 Variant <xxxxxxx> does not exist.
Message 00 564 Job cancelled after system exception ERROR_MESSAGE

Now you might ask: how did you know the missing variant is for step 2? Well, the message DB 612 shows the variant and the program name in Dutch whereas the English version (as above) only shows the variant name.

Today this batchjob has been created and executed 21 times today and 9 out of 21 times this error comes up.

What am i not seeing? What am i missing? Anyone with some pointers for me to look at?

Kind regards, Guus