Publish fails for large artifact - ant

Question

For a legacy project I'm currently introducing Ivy with Artifactory. I have some reusable scripts that work pretty well for jars and zips with sources. However, now I need to publish several large artifacts - zip-files, largest ~150MB. The publish fails with the following error-message:
impossible to publish artifacts for com.siemens.nucleus.tmbo#TMBO-RELEASE;1.6-SNAPSHOT: java.io.IOException: Error writing to server
Caused by: java.io.IOException: Error writing to server at sun.net.www.protocol.http.HttpURLConnection.writeRequests(HttpURLConnection.java:578)
A workaround is to change the order of artifacts: small one first. It seems it has something to do with authentication - ivy seems to try with anonymous first, if that fails it tries with the configured user, but in the error case it only tries with anonymous, but twice (interpretation of Artifactory's access-log).
I'd rather go with a solution than a workaround - any ideas? Can I force ivy to always use the credentials?
Here is my ivy.xml:
<?xml version="1.0" encoding="ISO-8859-1"?>
<ivy-module version="2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="http://ant.apache.org/ivy/schemas/ivy.xsd">
<info
organisation="myorg"
module="mymodule"
revision="1.6-SNAPSHOT"
status="integration" />
<configurations>
<include file="${ivy.confs.file}" />
</configurations>
<publications>
<artifact name="large_artifact" ext="zip" type="deploy" />
<artifact name="small_artifact" ext="zip" type="deploy" />
</publications>
<dependencies>
<!-- None. -->
</dependencies>
</ivy-module>
EDIT:
ivysettings.xml:
<ivy-settings>
<settings defaultResolver="default" />
<include url="ivysettings-shared.xml" />
<include url="${ivy.default.settings.dir}/ivysettings-local.xml" />
<resolvers>
<chain name="default" returnFirst="true" checkmodified="true">
<resolver ref="local" />
<resolver ref="shared" />
</chain>
</resolvers>
</ivy-settings>
ivysettings-shared.xml:
<ivy-settings>
<!--Authentication required for publishing (deployment). 'Artifactory Realm'
is the realm used by Artifactory so don't change it. -->
<credentials host="my-url.com" realm="Artifactory Realm"
username="${ivy.repo.my-company.username}" passwd="${ivy.repo.my-company.password}" />
<resolvers>
<chain name="shared">
<url name="my-releases" m2compatible="false">
<artifact
pattern="https://my-url.com/artifactory/my-releases/[organisation]/[module]/[revision]/[type]s/[artifact](-[classifier])-[revision].[ext]" />
<ivy
pattern="https://my-url.com/artifactory/my-releases/[organisation]/[module]/[revision]/[type]s/ivy-[revision].xml" />
</url>
<url name="my-snapshots" m2compatible="false">
<artifact
pattern="https://my-url.com/artifactory/my-snapshots/[organisation]/[module]/[revision]/[type]s/[artifact](-[classifier])-[revision].[ext]" />
<ivy
pattern="https://my-url.com/artifactory/my-snapshots/[organisation]/[module]/[revision]/[type]s/ivy-[revision].xml" />
</url>
<ibiblio name="my-external" m2compatible="true"
root="https://my-url.com/artifactory/all" />
</chain>
</resolvers>
</ivy-settings>
ivy.repo.my-company.username and ivy.repo.my-company.password are defined in a properties file %IVY-HOME%\security.properties