A new register of UK institutions approved for visa applications by overseas students is having problems.
The register lets potential students check college's credentials
The web-based register, launched last month, was developed by the Department for Education and Skills as a way of clamping down on bogus colleges.
But some students have also been refused visas because genuine centres' addresses were not all listed.
The register provides a way for students to check if an institution they are interested in is genuine.
It also allows immigration staff in the UK and abroad to check whether someone seeking a visa is going to a bona fide college.
And the list includes diverse institutions such as a coffee bar in Nottingham, Holloway jail and even the Archbishop of Canterbury.
One particular problem arose with institutions which have multiple campuses.
The recently renamed University of the Arts London, for example - famous alumni including Stella McCartney, Sir Terence Conran, John Hurt and Antony Gormley - has some 18 constituent parts.
One of its students was refused an extension of permission to stay because not every address was on the register, said Duncan Lane, director of advice and training at the Council for International Education (UKCosa), which looks after students' interests.
The university was alerted and quickly corrected the error.
But an overseas student thinking of applying to an institution in a similar position might have concluded it was not genuine and looked elsewhere.
"It can damage the reputation of the institution," he said, "so they are very sensitive to that."
"This has happened a few times that we know of."
Universities UK - representing the bigger institutions - said it would continue working with all involved "to resolve any outstanding issues".
But the other side of the coin is that some institutions are listed which on the face of it have no connection with foreign students - such as the Unique Coffee Bar in Nottingham.
What's in a name?
"It's a surprise to us," said its development manager, Gemma Thorpe.
The reason is that the register was compiled using lists of training organisations provided by funding organisations - which is how prisons come to be on it, for example.
The coffee house is also an alternative education provider, working with youngsters who are not getting on in mainstream schools.
"We have not had any foreign students," Ms Thorpe said - and nor is she looking for any.
UKCosa's Duncan Lane said: "On the face of it, it doesn't cause any harm because that coffee shop isn't going to abuse its position and say, great, let's make loads of money and recruit students from China."
He thinks probably it is just a question of teething troubles.
"We could be making a lot of noise about something that's just a bit quirky."
But if such organisations which are on the register were taken over by underworld gangs in some of the countries that export "students" to the UK for other purposes, there could be a problem, he said.
The DfES said the issue of organisations with constituent parts had now been addressed.
It and the e-learning organisation Ufi were compiling a new register of learning providers which would have a much broader purpose.
"Individual learners and employers will be able to find out about the learning provision available in the UK and the quality of that provision," a spokesperson said.
An initial version will be operating by the end of this year, with a full register in place by autumn 2007.
And the reason for the inclusion of the Archbishop of Canterbury?
"Listed by virtue of degree-awarding powers granted by the Pope in 1533," according to the Times Higher Education Supplement, which has been investigating the register.