Unable to submit some files for analysis.

From ‘My Pending Files’ I am attempting to submit an exe file for analysis. I have tried several times but, on each occasion, about 75% of the way through it fails with an error message ‘Connection with the server was terminated abnormally’, or similar. Many other files have been successfully submitted. The exe file is 13.9MB. So far it is only with this file I’ve had a trouble. Is the large size the problem? I have no other problems with my broadband internet connection.

32-bit Windows XP Home SP2, AVG Free Edition, Comodo Firewall 32-bit v3.0.13.268.

Installers cannot be submitted.