HTTP Error on image upload

Hi – hope I can get a bit of help with this – I’ll be as exact as I can
I’m having a nightmare since the last 24hrs as I cant upload any images without getting the dreaded HTTp error messsage.

I have a GoDaddy managed WordPress account and yesterday started getting the HTTP Error message on image uploads.
I contacted Go Daddy today and after 3 phone calls to support we are not really any better off but we have found we can upload images with no problems when the theme is deactivated. They’ve asked me to ask if there have been any new updates that could have caused this and if I need to make any changes to php memory requirements?
I had them up the memory execution to 256M today and thats all gone ahead – they thought it might have helped…sadly no so more phone calls and more help and the last support guy was great and said that this happens quite often (apparently) and I need to find if any changes have been done…..if so, what numerical changes I can pass on to them at the GoDaddy side.

Im not massively technical but I will try anything as Im having to deactivate the theme each time i do an image uplad – not handy at all.

Can anyone help at all ?
Thanks
Hamish