glRotatef scaling up and down on ortho projection?

I’m using an ortho projection and I don’t know why but when I call glRotatef the shape just scales up and down!, what could be the problem here?. I’m pretty sure I’m set onto the modelview matrix and my stacks are ok, its really the first time I see this type of behavior.

thanks.

OK this is weird… I was doing this: glRotatef(myRot, 1, 0, 0);

it seems like using 1 is the problem here… if I use 0.99 it works ok… Why is this, how to prevent this?

Thanks.