7.10.1 and custom fields

Hi!

About 3 months ago, I added a 10 char text box field to my enrollment forms.
It holds a date, but it is text

It has been working just fine, but after we upgraded to 7.10.1, it has begun to not save when data is entered or changed, and cause the rest of the page to fail upon saving for any field, if there is previous data in the field.

Has there been issued with customization for this version, or maybe it has something to do with the custom fields being changed?

If someone has an idea, I would sure like to hear about it....