I have block with two properties. String and XHtmlString property.
Changes in XHtmlString property not saved.
Steps to reproduce:
1) Write some text in XHtmlString property.
2) Click outside XHtmlString property.
Publish button isn't activated. After page refresh, entered text is lost.
If I write text in String property, click outside, publish button appears. But XHtmlString property value not saved.
How I can save XHtmlString property value:
1) Do changes in String property.
2) Click "Revert to published".
Now XHtmlString property work as expected.
Update to latest version will fix this issue. (I assume you are on 7.5)
till then Use IE, Wait for few secs before publishing OR Last field that lost the focuse should be other than xthml string.