Crazy freezing in ASP.NET 1.1 application

[m m]

I'm developing an ASP.NET 1.1 application which produces several bar-
code images (PDF417 format).
The bar-code producer is a class that converts clear text into bar-
code bitmap using a special font.

I've embedded my font as resource in the main assembly to extract it
during run-time.
I tried to load the font via memory stream or producing a real file
and loading it through AddFontFile (instance method of
PrivateFontCollection class).

Both methods work for a while... but after one hundred or two hundred
cycles the execution stops.
In debugging mode, VS shows me that the execution stops randomly in
various point of my code; especially in rows where I use GDI
instructions (for example sometimes freezes in the instance of
PrivateFontCollection, other times in the request of Font instance
attributes...)
The strange thing is that .NET doesn't throw any exception. It stops
execution and waits for something.

I checked GDI object or Handles in task manager but I didn't see
anything strange.

To partially solve the problem I've installed the bar-code font in
windows and now I instance it with usual instruction: Font myFont =
new Font("Arial", 10);

Anyway I'd like to know why my code freezes when I try to load
dynamically the font.

Thank you

Gianluca N.
[epikarma]