QTP Error *E* Item specified for index not part of subfile include list

[Elisabeth Corsten]

Hello List,

can someone make out what's wrong with the following QTP code?

> acc file1
> subfile x1 keep include id-p, id-ctrl index id-ctrl unique
*E* Item specified for index/segment not part of subfile include list.

We tried this two-liner after other strange behavior of the nightly
batch - the QTP failed on an update from an indexed subfile to a
db-file, declaring there was no linking value for the update (after
having established just that in the initial linkage "records read"...).
Re-running the QTP in question was sweet and faultless!

(environment HPUX, PH newest version)

Any ideas are welcome, many thanks in advance
Elisabeth