"The biggest user concerns are still in the traditional skills purchase such as programming skills like RPG," warned Mark Walas, from the City of London-based firm, Sierra Training.
He called on IBM to launch more UK training initiatives for the iSeries and its predecessor, the AS/400.
The UK's AS/400 users are facing a skills shortage ranging from programmers through to systems management. There are fears that the platform will be unknown to the next generation of IT professionals.
The iSeries, which is perceived as a niche server, is becoming increasingly less popular on university campuses.
Walas said, "A number of computer science graduates don't really know what an AS/400 is."
Some students have not even heard of the platform.
Users are calling on IBM to raise the server's profile by working more closely with universities and specialist training firms.
There are also worries about shortages in some of the newer skills. Bill Benjamin, vice-president of iSeries e-business specialist Lansa, said, "It is still hard to find people who really understand AS/400 Web development and design."
He urged IBM to devote more resources to programmes such as Partners In Education (PIE), which is designed to introduce students to the iSeries by forging links with the IT industry.
Walt Ling, IBM's vice-president of customer satisfaction and technical support, admitted that the UK's involvement in PIE was not as extensive as the US but promised that this would change.