[Rpm-maint] strange dependency issue

[Tom Brown]

Hi

First of all i apologise for masking the names of the rpm's but they are 
sensitive.

I have built an couple of rpm's and the latter depends on the former and 
for some reason i am getting the following

# rpm -ivh ../RPMS/noarch/xxx-sun-java-custom-1.4.2_13-3.noarch.rpm
error: Failed dependencies:
    xxx-sun-java-1.4.2_13-3 is needed by 
xxx-sun-java-custom-1.4.2_13-3.noarch

but

# rpm -qa | grep xxx
xxx-sun-java-1.4.2_13-3

am i missing something blindingly obvious here as the requires section 
in the .spec is

Requires: xxx-sun-java-1.4.2_13-3

any ideas ??

thanks