Need help on this one please - Pioneer 110D

Strange one this. I have used Verbatim DVD+R 16x certified media for ages - no problem. Recently burns have appeared to burn & verify OK but when I try putiing the media back into the drive it says that the disc is blank. However it can’t be as I’m unable to write to it again. Old disks written by this drive read fine. I uninstalled all the buring S/W on my pc. Problem still occured, ie. My Pioneer 1110D (Lastest F/W) will not read disks it had recently written to. If I open “My Computer” in windows with no dvd’s in the drive then the label on both says “DVD-RW” (E) & “DVD-RW” (F) respectfully. However If I put one of the recently written to DVD’s into Drive “F” which is an Asus 0402P/D then the drive reads the disk fine & The Disk label shows up in "My Computer " with the title of the disc changed to the current disc.If I remove the Disc & put in back into the Pioneer “E” Drive then then the drive spins up, the light flashes, then nothing. If I go to “My Computer” then look at the drive then I notice that the label had changed to “CD Drive” (E). If double click on this to open the DVD I get “E:\ is not accessible” & under that it says “Incorrect function”. I have had the Pioneer for a year & have burnt DVD’s most days - could it be worn out. I suspect the burning power is not stable. :sad:
Also my Verbatim disks burnt on other people PC’s seem to work!

Please can anyone give me any advise or help?