Thumbnail picture for PSP playback sometimes not generated

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Selecting the PSP AVC preset
2. Encoding a file
3.

What is the expected output? What do you see instead?
I expect to see both the thumbnail file and the video file, but I only see the 
video file.

What version of the product are you using? On what operating system?
v5.0.37.8 r161 on Windows 7 Ultimate 32-bit

Please provide any additional information below.
This does not happen all the time, but I've yet to find a pattern with the 
files that I have converted.

Original issue reported on code.google.com by tech15en...@gmail.com on 28 Jul 2010 at 7:57

[GoogleCodeExporter]

If I reconvert the same file, the thumbnail will be generated.

Original comment by tech15en...@gmail.com on 28 Jul 2010 at 8:01

[GoogleCodeExporter]

Did you see any error messages in the log? Something like:

CREATING THM
------------------------------
Saving picture to: F:\Yvan & Dan Daniel - Enjoy Thebb Silence (16x9).png
PNG 144x80 

Error creating THM: bla-bla-bla

Original comment by forc...@gmail.com on 4 Sep 2010 at 7:45