Thanks hv. The change must have been between 5.004_04 and 5.004_05 since with my 5.004_04 I get the old style behaviour.

Totally agree about warnings - but this code wasn't written by me! It has been in production for several years (with warnings turned off!) and this issue has only come to light just now with an upgrade to 5.8.0.

Anyhow since the solution is to change from {} to () and it only happens in 2 or 3 places, I'm not too worried about it.