help for reducing sugar analysis

[D. Vadnais]

I have tried to use the Nelson-Somogyi method for determining reducing 
sugars released by invertase activity.  I have not been able to make it 
work because of bubbles forming on the sides of the cuvette when I put 
the samples into the spectrophotometer.  I was wondering if anybody else 
has had this problem, and what they did to correct it.  I have tried the 
method as outlined by Somogyi in 1951.  Any suggestions?  Please reply to 
my e-mail address: dvadnais at crop.uoguelph.ca
Thanks.
Dave