UNEXPECTED ERROR when attempting to create records via client side script

This only occurs on some machines in our office, so I believe that it may be some sort of browser config issue.  It does not appear to be browser version dependent.  We're using IE.  This simple client side 'on save' script works on some machines, not on others (this is on a Bill transaction):

function storedcoincheck()
{
// Test ability for brower to createrecord.
alert('Attempting to create custom record');
var record = nlapiCreateRecord('customrecord10');
alert('Record successfully created / not submitted');
return false;
}

I get the "Could not submit the form due to an unexpected error" message.

customrecord10 is a valid custom record and gets created just fine on some installs of IE.  The problem does not follow a particular user or role.  If it fails on a particular maching, it fails for every user on that machine.