What steps will reproduce the problem? 1. Set CPU Clock XMB + Game to Default 2. Start Mame4All PSP v4.9r2 3. When game list shows up, select any game, press Start 4. Game options menu appears

What is the expected output? What do you see instead?

Expected: navigate and change options with arrows, start game with Start button. Instead : Arrows do not react, buttons do not react, except Playstation button to leave the application

What version of the product are you using? On what operating system?

6.39 Pro-B6 on 09g but seen on other units + Pros, too

Please provide any additional information below.

Set both CPU-clocks to 366/166 and anything works fine

I'm having this same issue on 6.60 Pro-B10 on a PSP-1000. I'm soooo looking forward to a fix for this!

Set clocks to 333 Mhz. It won't lock up then.

As ssh3mk said, you need to set your clock to 333mhz.