Of course, these errors are not related with the DB object at all. My fault, I was wrongly interpreted your term "DB error messages".
Most probably these error are generated in the code behind and there is nothing you can do. Unless there are some tricky hidden settings (in registry maybe) to disable such thorough error messages. I don't know... :\
But in case if you will not find a better solution you may try changing the portal error messages by using some javascripting "on the fly".
These are the steps to get that:
* Check if you have jquery library reference in LiteMaster.htm. It should contain somehing like this:
<script language="javascript" src="jquery-1.4.2.js" type="text/JavaScript"></script>
* Modify LiteError.htm by ading this script at the end:
...
<script>
$( ".AlertContent" ).html("My Dear Portal User,<br/><br/>Something slightly wrong has just happened in the system.<br>But please do not panic, everything is under control. Unless we haven't been informed about it yet.<br/>So we are kindly asking you to call us by the number 123456789 and tell us about your last actions here.<br/><br/>And thank you for being our customer!");
</script>
</body></html>
* Recycle IIS Application Pool used by VSM Portal.
* Try to get some errors within the portal.
Regs, Gytis