Hi jackwabbit
my daughter was diagnosed as "mild clumsy child syndrome" in the 90's, she has 9 GCSE's and a National Diploma in Health Care. she struggle throughout school and college, was bullied for her posture and her naive childlike behaviour. She went to university but it all became too much for her and she left in year two.
My daughter has now been sacked or managed out of at least 6 jobs. Not because she does anything deliberately wrong or maliciaous, just because she is different. She has bee n very depressed, cries very easily, hates change, and her self esteem is so very low 9just having been "let go" again.
I know what you mean about help and diagnosis, the health service seems to think that once you are an adult you have no need of a diagnosis!
My GP has referred her because we have looked at the DANDA site and think she is also on the Autism spectrum scale (possibly Aspergers) which is commonly connected to Dyspraxia. It sounds from what youare saying the your son may be on that spectrum as well. THis was the only way we were able to get a referral for further investigation under the nhs.
We are in the horrible ESA/JSA situation as well, as she is 24 and wants to have her own independent life, but can't keep a job for long enought to save or make any future plans.
I wish you well, and think you should consider taking the DWP to court under the Disability Descrimination Act, or at least use the act to threaten them with.
I know how immensly tiring it is to keep fighting the system and trying to do your best for your child, and hope you eventualy have some success, and more importantly less anxiety ofr your son. All the best

!!! Karen