Reading a +RW on another DVD player?!?

[stefmit <stefmit@comcast.net>]

Just got my first DVD burner yesterday (Sony DRU510A), installed it 
immediately on my trusted Linux box, formatted and growisofs-ed a whole 
directory onto it (media is a Phillips +RW DVD). Checked it afterwards, and 
was able to read it. Brought it to work, and plugged it into a Ricoh 
DVD/CD-RW, and was not able to mount it ... I am assuming because that drive 
cannot read the DVD +RW (?!?). 

My question to you would be: do you know of any limitations of the Ricoh 
MP9060A in regards to play back of DVD +RWs? I was looking through the 
document at http://fy.chalmers.se/~appro/linux/DVD+RW/
but could not find anything related. The only indication was about how to 
write to the appropriate Ricoh DVD burners, with firmware upgrades, but no 
mention about readers compatibility. 

The Ricoh web site in regards to this model and history of firmware has no 
hints in regards to changes on the DVD reading area.

TIA,
Stef