Error message in InfoPath after MUI installation of swedish lang files for Office

After the installation of the MUI swedish language files on our Sharepoint server, the following error occurs:
if you have any multiline fields in your InfoPath forms, like RTF fields, you are no longer able to mail those forms!
Really strange error, I know - but my world is full of strange errors.... I am so sick of it. The entire message reads:

Reference to undeclared entity 'nbsp'. Line 85, position 6559.
System.Xml.XmlException: Reference to undeclared entity 'nbsp'. Line 85, position 6559.
at System.Xml.XmlTextReaderImpl.Throw(Exception e)
at System.Xml.XmlTextReaderImpl.HandleGeneralEntityReference(String name, Boolean isInAttributeValue, Boolean pushFakeEntityIfNullResolver, Int32 entityStartLinePos)
at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos)
at System.Xml.XmlTextReaderImpl.ParseText(Int32& startPos, Int32& endPos, Int32& outOrChars)
at System.Xml.XmlTextReaderImpl.FinishPartialValue()
at System.Xml.XmlTextReaderImpl.get_Value()
at Microsoft.Office.InfoPath.Server.Xml.SafeXmlReader.get_Value()
at System.Xml.XmlLoader.LoadNode(Boolean skipOverWhitespace)
at System.Xml.XmlLoader.LoadDocSequence(XmlDocument parentDoc)
at System.Xml.XmlDocument.Load(XmlReader reader)
at Microsoft.Office.InfoPath.Server.Xml.SafeXmlDocument.Load(XmlReader reader)
at Microsoft.Office.InfoPath.Server.Xml.SafeXmlDocument.LoadXml(String xml)
at Microsoft.Office.InfoPath.Server.SolutionLifetime.DataAdapterEmail.GetViewHtml(XmlDocument input, String viewName, XsltContext xsltContext, Solution solution, Boolean cleanUpFormatting, String intro, String introSubmittedBy, ImageAttachmentHelper imageAttachmentHelper)
at Microsoft.Office.InfoPath.Server.SolutionLifetime.DataAdapterEmail.Execute(XPathNavigator input, String to, String cc, String bcc, String subject, String intro, String attachmentFileName, String viewName, Boolean sendAsInfoMail, EmailAttachmentType emailAttachmentType, XsltContext xsltContext, String xsnUrl)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.DataAdapterEmail.ExecuteInternal(XPathNavigator input)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.DataAdapterEmail.Execute()
at Microsoft.Office.InfoPath.Server.SolutionLifetime.RuleAction.EvaluateExpression(Document document, XPathNavigator currentTarget)
at Microsoft.Office.InfoPath.Server.SolutionLifetime.RulesRuleSet.<>c__DisplayClass7.b__4()
at Microsoft.Office.InfoPath.Server.SolutionLifetime.RulesRuleSet.EvaluateExpression(Document document, XPathNavigator targetNavigator)
at Microsoft.Office.InfoPath.Server.SolutionLifetime.ButtonFormCode.<>c__DisplayClass2.b__0()
at Microsoft.Office.InfoPath.Server.SolutionLifetime.ButtonFormCode.Click(Document document, XPathNavigator container)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.EventClick.Play(Document document, BindingServices bindingServices, EventLogProcessor eventLogProcessor)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.Event.PlayEvent(Document document, BindingServices bindingServices, EventLogProcessor eventLogProcessor)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.EventLogProcessor.<>c__DisplayClass1.b__0()
at Microsoft.Office.InfoPath.Server.DocumentLifetime.EventLogProcessor.ExecuteLog(Int32 expectedEventLogID)
at Microsoft.Office.InfoPath.Server.DocumentLifetime.Document.<>c__DisplayClass6.b__3()
at Microsoft.Office.Server.Diagnostics.FirstChanceHandler.ExceptionFilter(Boolean fRethrowException, TryBlock tryBlock, FilterBlock filter, CatchBlock catchBlock, FinallyBlock finallyBlock)

And the simple solution to this error is to replace your multiline field and replace them with "common" plain text fields. And, tada, you are able to mail the form again!