Does it happen with SDL 1.2.15?  Make sure you uninstall SDL 1.2.14 first...
http://www.libsdl.org/download.php

Thanks for your response.

It happens with SDL 1.2.15 too... Maybe the pentium G620 technology ?

Or clipped screen...

Do you have problems with the SDL test programs that come with the source archive?
http://www.libsdl.org/download.php

If not, can you post a simple example that shows the problem?

Created attachment 809 [details]
The most simple program

Created attachment 810 [details]
the result of this program

VERY VERY rarely, the program runs fine. So rarely that I lost patience trying to screenshot it.

The testblitspeed :
"Non-blitting crap accounted for 0 percent of this run.
63975 blits took 9972ms (6415fps).

( Sorry for triple post )

I ran an executable compiled by someone and it worked fine. But when I compile, bug happens.

(In reply to comment #7)
> The testblitspeed :
> "Non-blitting crap accounted for 0 percent of this run.
> 63975 blits took 9972ms (6415fps).
> 
> ( Sorry for triple post )
> 
> I ran an executable compiled by someone and it worked fine. But when I compile,
> bug happens.

Sorry for editing again. I made the same program but this time with a loop :

while(1)
    {
        SDL_BlitSurface(test, NULL, ecran, &whereTo);
        SDL_Flip(ecran);
        SDL_Delay(250);
        SDL_FillRect( ecran, 0, SDL_MapRGB( ecran->format, 0, 0, 0 ) );
        SDL_Flip(ecran);
        SDL_Delay(250);
    }

The first blit doesn't work, but all the other works great !

In the sample program you provided you are not filling out the whereTo width and height.  You must set those to the same values as the sample width and height.

When I learned SDL, I've been taught that w and h of the destination rect where not used by SDL_BlitSurface. Sorry for that. But even if I set whereTo.w and whereTo.h, it doesn't work at first time, but all of the next blit in the loop I wrote are working great.

while(1)
    {
        whereTo.x = -250;
        whereTo.y = -80;
        whereTo.w = 400;
        whereTo.h = 200;
        SDL_BlitSurface(test, NULL, ecran, &whereTo);
        SDL_Flip(ecran);
        SDL_Delay(500);
        SDL_FillRect( ecran, 0, SDL_MapRGB( ecran->format, 0, 0, 0 ) );
        SDL_Flip(ecran);
        SDL_Delay(500);
    }

The sample.bmp dimensions included with the SDL tests are 408 x 167

Sorry for being insistant, but even if the right w and h it doesn't fix the problem...

I haven't been able to reproduce it here.  Have you tried debugging it and see what's happening there?

Debugger says :
Warning: GDB: Failed to set controlling terminal: Operation non permited

I don't know if it can help you, but I tried another code.
Like I said, blit and then flip doesn't work. But it works great with a SDL_Delay before.

SDL Initialization :
Blit
Flip
//Doesn't work

But :

SDL_Delay(100)
Blit
Flip
// Works fine.

The problem seems to lie completely elsewhere.
I can reproduce it...if whereTo.x = -250;whereTo.y = -80;
but not if whereTo.x = -250;whereTo.y = -80;.
Is that a good enough hint ?

Seriously though, I haven't really (or fully) investigated it, but it comes down to something simple: SDL_BlitSurface modifies it's destrect argument, so this is not quite a bug, just a not quite expected behavior.
On any subsequent iterations after the first one with the given in comment 5 test data (both code and sample.bmp), whereTo.x==whereTo.y==0.

So, the first result (the small update in the corner) is actually the correct one.

...a typo; it was meant to read
"...but not if whereTo.x = 250;whereTo.y = 80;...."

Can't it be the result of the OS ? I have two computer with Ubuntu, the two of them have the same bug and this bug disapear with a SDL_Delay just after SDL_Initialisation... But without SDL_Delay, no matter wich w or h was set, the screen seems to be this small square.

* "no matter witch w, h, x or y was set..."

Try something like this:
for(i = 0; i<7; i++)
    {
        //SDL_Delay(2000);
        SDL_BlitSurface(test, NULL, ecran, &whereTo);
        //fprintf(stderr, "rect x: %d, y: %d\n", whereTo.x, whereTo.y);
        whereTo.x = -250;
        whereTo.y = -80;
        SDL_Flip(ecran);
        SDL_UpdateRect(ecran, 0, 0, 0, 0);
        SDL_Delay(2000);
        SDL_FillRect( ecran, 0, SDL_MapRGB( ecran->format, 0, 0, 0 ) );
        SDL_Flip(ecran);
        SDL_Delay(250);
    }

(longer delays, so you can actually see the result)

Result is consistent then - on each blit only the small area in the corner is affected. TBH, only part of this behavior, that's unexpected, is that input rectangle (that is data initially provided) gets modified.

Looking at the source, it seems to be due to the solution chosen to pass data between _UpperBlit and _LowerBlit.

I have the same problem... It seems that the problem is the screen surface, because even operations like SDL_FillRect() only fill a small part of the screen. Also it only happens on the first time I use the screen surface, after I do anything else it behaves as expected...

Created attachment 855 [details]
Simple bug test

BTW: I'm also using Ubuntu (12.04 - 64 bits) and my sdl version is also 1.2.15

I've tested the exact same code compiled in another machine with Ubuntu (11.10 - 32 bits) and SDL 1.2.15 too, and the bug was gone...

You need to set whereTo.w and whereTo.h

Rubinson Ivan is correct.