NEC ND 6450 not writing DVD's

Hi there, i hope you can help me here. I’m trying to write a DVD but nothing. It’s not doing it any more.I’m using the same media as always, Maxell DVD+R
If i use CopytoDVD i get the following error “Power calibrating error, writing device might be dirty” i went ahead and cleaned it. Same result. What ever software i use i get the same result, can’t burn. I can record and play CD’s and play DVD’s but can’t burn them. I think it’s a hardware issue. I read a lot in your forums and wanted to upgrade my firmware but first , i don’t know what’s my version and second, i don’t know what’s the best one for my writer.

Could you please tell me what to do? i will really appreciate it.

If it helps, i’m using a Compaq V2030US