An update on where I'm at with this, I did a clean uninstall/re-install of the DM manager and all folders, registry sweep as well as delete all registry entries to do with RIM/Blackberry and I still get the handheld application error when using my works PC computer.
I also upgraded my phone OS to 6.2647 dowloaded from o2 without problems.
When I got home and backed my phone up to my laptop without any issues I had a quick look at the versions numbers and noticed I am using the most up to date DM and phone OS but the Device Manager was 6.0.0.31 where as my work PC was 6.0.0.30
Could this have some bearing on the issue? The question is where does the Device Manager come from, is it installed as part of the Desktop Software and can the Device Manager be upgraded seperately from somewhere else?
Another thing I'm confused about is the software application loader I dowloaded from o2, does this interact with the desktop software or is it a totally seperate bit of kit? Can I keep different software versions on the same PC without problems? For instance I have two blackberrys can I keep the most up to date version for each phone on the same pc without any conflicts?
I would apprecate any help on this.