no good news...i don't know exactly which app messed it up but after some juggling yesterday i found that my bluetooth was unable to receive files from other cells or from the pc either...

(tried all the possible settings but was really a problem and not a configuration error)
It is not the first time that i fall in this kind of problems after installing some utility...
Just to let you know : i've tried out phonealarm and this one (not related with the SMS problem) :
EyePhoto - Windows Mobile Photo Viewer
As i said i don't know if one of the two was the responsible...but before them the bluetooth was ok...
Hard reset solved but very annoying...
anyway thanks for the replies i will try the others after some reading on the forums about other users experiences before going into troubles again...