Twenty Ten theme menu problem

That is not the original Twenty Ten theme. Re-upload a fresh, unpacked, copy of the Twenty Ten folder to wp-content/themes using FTP or whatever file management application your host provides.
https://www.ads-software.com/themes/twentyten

Thank you for your quick reply, esmi.
Your advise reminds me of the old Microsoft joke:
A car with 4 engineers suddenly stalls. The Microsoft engineer solution: Lets all get out of the car and then in again. That should do it!
I take it this forum is not right one for my problem. My bad…
Best regards,
OT

You might check on these two CSS errors – IE doesn’t like invalid code:

https://jigsaw.w3.org/css-validator/validator?uri=http%3A%2F%2Fwww.jacobswell.com.au%2F&profile=css3&usermedium=all&warning=1&vextwarning=&lang=en

/* This is the custom header image */
#branding img {
	border-top: 4px solid #000;
	border-bottom: 1px solid #000;
	display: block;
	float: left;
	<!--border: 0px solid black;box-shadow: 10px 13px 5px #888888-->
}

/* =Menu
-------------------------------------------------------------- */

#access {
	background: #00342D;
	display: block;
	float: left;
	margin: 0 auto;
	width: 940px;
	<!--border: 0px solid black;box-shadow: 10px 10px 5px #888888-->
}

<-- .... --> are HTML comment tags
CSS uses /* .... */

BTW, esmi’s comment was based on the inadvisability of modifying a default theme rather than using a child theme –

https://codex.www.ads-software.com/Child_Themes

Hi WPyogi,
Thanks for that, much appreciated.
Just goes to show: “A little knowledge is a dangerous thing!”
Thanks also for the BTW – I wasn’t confident enough to use a child theme (but reckless enough to muck up the default theme).
aveagoodweekend…
OT