Session_Start problems

[Jason Lehman]

When testing on my local machine, the session_start fires fine. I try
storing a value to my database, creating a timestamped text file, and
writing a line of text to a general log file. All of these work. When
I transfer my site to my webhost, all of these no longer function
within the session_start. All of these functions work correctly when
triggered by button clicks or page redirects, the session_start simply
won't fire. I have 3 other sites hosted with this same company, and I
do the same type of things in each of these sites with no problem.
Right now, just to check if the event is getting fired, I have the
session_start attempting to convert the letter "S" to an int32. Again,
breaks locally, has no problem on my webhost.

protected void Session_Start(O bject sender, EventArgs e)
{
Convert.ToInt32 ("S");
}

Any ideas are greatly appreciated?