This problem has gotten worse since sp1 in that often I am unable to put a 240/10000 in the des restriction page. It wont take it, i'll execute and then it disapears. Now today it finally happened on the climb page as I was departing KMDW through 5000 the climb restriction 250/10000 disapeared after I went direct JOT (there were no leg restrictions in speed or altitude at JOT). I busted my speed and hit 290 KIAS before I noticed it. I am now getting violated by Radar Contact! Anyway this is fairly frustrating and I am not sure if I am doing something wrong. I dont think I am because it worked before and now the climb is affected. After the climb restriction disapeared I was also unable put it back in there. It would say invalid entry.

Is there something simple I am overlooking here?

There is a footnote in FCOMv2 when ever it talks about the setting default speed restrictions. Could this apply in your situation?---Note:If the FMC default speed restriction is overwritten, it will be deleted and not return after the overwrite condition passes (e.g. the default of 250/10000 is overwritten to 230/3000, after 3000 feet is passed there will be no speed restriction and VNAV will accelerate to the unrestricted climb speed).---