Migrating up to 2.0.26. Strange thing on checkout

[Sadruddin]

I'm slowly and carefully upgrading from 2.0.20d

I'm fine up to 2.0.24c

Then when I try the next big leap to 2.0.26d I have a problem.

Everything seems to work fine re: displaying products, adding to cart, and then displaying the cart.
BUT
When I try to go to checkout - I only use PayPal standard - instead of going to PayPal, it displays the "Your Account Details" page, even though my account details are displayed on the cart page.

I'm really psyched and impressed how easily things have gone so far, but this has me stumped.
Actually, after a little further investigation, this happens from 2.0.26a.

Help?

[jenkinhill]

Using any form of SEF?  Commercial VirtueMart template?  Is One Page Checkout enabled?

[Sadruddin]

Hi.

No SE.
No custom modules, as far as I know.
How could I find this out, please, if I am?
And no commercial checkout template, though I have made one or two css changes to the standard template.
As above, though, how could I find out whether I've overlooked something and am, in fact, using a commercial template?

Thanks for the help.

S

[jenkinhill]

See if One Page Checkout is enabled in Configuration/Checkout. If it is, try disabling it.

[Sadruddin]

One Page Checkout wasn't set, but "On checkout, ask for registration" WAS set.
It's possible that this is what's happening, so I'll check.

[Sadruddin]

OK.
I've come back to this after a busy time elsewhere.
"On checkout, ask for registration" makes no difference.
Everything is fine up until 2.0.24
But when I go to 2.0.26a I get sent to my Accounts Details page.
OPC isn't enabled.

Help?  Please?