No it's not just you! Here are a couple of tips, courtesy of member kbalona. They work for me most of the time:
>>>>>>You might want to clear you cache & cookies.
To prevent losing your listings from timeout you can do two things, first, and best, is when you're done working on the listing, click on one of the add image buttons, like you want to add another image. When the window opens for you to select an image, if you've timed out it will ask you to sign in (in the popup window). If it says that, sign back in. Then go back to your new listing, and click save. But if the popup window opens and allows you to select an image, then you haven't timed out.
Another way is to press the back button when you click save and it asks you to sign in. While that works a lot of times, I've had a few times when it didn't. The first way is more reliable. <<<<<<
Although one time I was logged into Auctiva for over a WEEK, never got kicked out once. Still can't figure that one out!!