I've been using Preview for ages to look at my photos to quickly switch from horizontal to vertical format, decide which to delete (blurred, for example) and in what folder to save them. I also use the tools to sharpen those that need it. Generally, if they need more corrections, I correct them in Photoshop later.

But this is my latest problem. If I open up more than one photo & use the tools to make minor corrections, then when I close the window and it asks me if I want to save changes it will save some, but then it starts beeping at me and won't save others. Then it adds a ~ before the .JPG making a image title to something like DSCF1000~.JPG Then I have to go in one at a time, take out the ~ in the title, then open one photo, make a correction and save it. I used to be able to make corrections on many and save dozens at a time.

Previously, when I chose a group of photos to open, let's say numbers DSCF1001.JPG to DSCF1025.JPG, it would display them in numerical order. Now the order is all over the place.

I am using Preview 3.0.9 on OS 10.4.11.

I have been using Macs for 25 years, but admit I am pretty hopeless when it comes to how they work or what can cause a problem like this. (Mine have been so reliable, I have rarely needed any help.)