“There is something wrong with these files …”

The desktop technician solved the problem himself, with the comment

There is something wrong with these files …

but didn’t realise it.

Microsoft PowerPoint XP was crashing whenever the customer was trying to open a particular set of files.

Google should have been his friend here. aka Let Me Google That For You : [...]

I don’t know how they got a TAB into the filename,

but they did.

Had a report from a user of LNME, that LNME was producing an error message, then crashing.

The cause that an message attachment had a TAB character in it’s filename, and Windows wouldn’t accept that, so it would error. (how the TAB got into an attachment name is another question… [...]