oldtony
Really no one can help you, as support for sme7.x was stopped long ago, & most users here would probably have forgotten the issues with sme 7.4 & 7.6 etc. I do vaguely recall a problem maybe similar to yours but the memory is sketchy.
Did you run both commands ?
ie
signal-event user-delete anita
db accounts delete anita
Also sme v7.6 was released in May 2012 see
https://wiki.contribs.org/SME_Server:7.6so you are running a version 7.4 that had later updates released for it.
You possibly/probably have hit a bug that was fixed in a later release eg 7.6
You could try updating but it is a difficult procedure as all the repos were moved to the obsoleted tree & it may be difficult to find them & reconfigure your server repo settings to use those external repos.
Descriptions have been posted in these forums previously, but it is not something to do if you do not understand repos & various issues associated with updating old versions.
It would be better & easier for you to upgrade at least to sme 8.2, so that you have something current you can get support for, & then consider to soon upgrade to sme 9.x.
The upgrade to sme8.x should be easy enough.