problem with conflicting web-apps

i have a problem with conflicting web-apps running in ibm websphere 4.0.7

i think the problem is caused by the combination of module-visibility being set to SERVER (it needs to be for other reasons), and my packaging policy - see below

thanks for any help

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web-app-1 consists of two "types" of components - the CORE classes which handle XML-to-HTML transformations, and the ADD-ON components which are handler classes to retrieve the XML data, and a set of stylesheets specific to this web-app

the web-app also contains a number of .properties files which are used to specify which ADD-ON handlers and stylesheets should be used - based on the contents of the HttpRequest - i.e. they tie together the CORE components and the ADD-ON components

a typical call to web-app-1 looks like this ...

1. one of the CORE servlets interrogates the HttpRequest
2. based on parameter values the servlet invokes one of the ADD-ON handlers
3. the ADD-ON handler retrieves the data, as XML
4. the servlet then invokes CORE transformation classes which transform
the XML into HTML using one of the ADD-ON stylesheets

the application works perfectly well

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then i built web-app-2 based on the same CORE classes as above, but with different ADD-ON handler classes and stylesheets

the CORE classes for both web-apps are identical and are all in package a, web-app-1's ADD-ON classes are in package b and web-app-2's ADD-ON classes are in package c

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the problem is, when both web-apps are loaded, and the app server is bounced, the first call to either of the web-apps causes the CORE classes to be loaded into memory - FROM WHICHEVER WEB-APP WAS STARTED FIRST

so if web-app-1 was started first, and the first request after the bounce is for web-app-2, the CORE classes are loaded from web-app-1, then the .properties processing continues with the web-app-1 .properties files -
and i end up running web-app-1