Syntax Error in Field Routine

Hi, I'm hoping someone can help me with a problem with a BI 7.0 Transformation Rule. I'm currently getting problems transporting a Transformation betwen a Development and QA client. Specifically, a routine in a Transformation Rule is showing a syntax error message during the activation process:

"Syntax error in GP_ERR_RSTRAN_MASTER_TMPL, row 466 (->long text)"

the diagnosis for which starts:

"Field <L_RECORD_NO>" is unknown. It is neither one of the specified tables nor defined by a..."

I've ensured that the related datasource is replicated and activated. I've also used the RSDS_DATASOURCE_ACTIVATE_ALL program to ensure the associated datasource is active, but I am still getting the problem. I've also re-transported the related extractor to the from the Development source system to the QA source system, and then carried out the replication process again, but I still can't seem to get the Transformation to transport successfully.

I can't seem to relate the field "<L_RECORD_NO>" to our transformation rule or our related datasource - I don't know if this is a special field symbol or variable being referred to behind the scenes.

I'd appreciate any help or advice anyone may be able to offer on this.

Many thanks,

Jeff.