Problem when custom password field contains a quote character

We have a custom password field defined as MixedCase on a custom table on our HR 9,1 PT 8.52 system.

When this field contains a single quote, the page used to access it never loads, the "throbber" just keeps going round and round.

Interestingly enough we have theis same custom table and custom field on our FS 9.1 PT 8.51 system.

There the same page works whether the field contains a quote or not. On both systems, the page display format is "Password".

Anyone have any ideas why this should be the case?

Thanks

Stan