Dear Manuel,
I just checked it with stock IE 6.0 under XP SP3. And still this same problem:
"{user notabs}"
changed to "undefined" every time when user open "Edit theme file - Main page template" comes from
phpclasses.org/design.html
"Design site themes ... Theme name ..." even "Save and preview" was clicked already before "Back to files list".
I also used "Reset to initial contents" and change {user notabs}:
[code]
<div style="margin-bottom: 8px;">
<div style="float: left;">{logo}</div>
<div style="float: right;">{companylogo}</div>
<div><h1 style="margin: 0px; text-align: center;">{title}</h1></div>
<div style="clear: both;"></div>
</div>
{ads}
{horizontalads}
{navigation}
{user notabs}
{recommendpage}
{body}
{endnavigation}
{endseparator}
{credits}
[/code]
And now it looks:
[code]
<div style="margin-bottom: 8px;">
<div style="float: left;">{logo}</div>
<div style="float: right;">{companylogo}</div>
<div><h1 style="margin: 0px; text-align: center;">{title}</h1></div>
<div style="clear: both;"></div>
</div>
{ads}
{horizontalads}
{navigation}
undefined
{recommendpage}
{body}
{endnavigation}
{endseparator}
{credits}
[/code]