Runtime Application Crashing using scripted export routine

I've got a multi file runtime solution created with FileMaker Pro 8.5 Advanced on Windows XP. It has a fairly simple scripted export routine that

opens all files, shows all records in each file and then exports all records to a filepath set with a variable in the .fp7 format.

At the moment the runtime application is crashing, at different points, in the export routine. I've tried this on 4 different PC's now and it keeps crashing on all of them at different files (e.g after file 1, after file 3, etc). If I open the files in FM Pro 8.5 Windows and run the same script using the same account it works perfectly with no crashes so far.

Anyone experienced similar problems with a runtime application crashing like this or have any advice? I've reset all the export script steps several times just in case? I don't feel I can release the runtime application in it's current state when it continuously crashes when exporting.

Thanks,

Andrew