So far I never had a problem with my prints but last time I used two different labs and both produced too dark prints. I don't know too much about colour management so let me ask you some basic questions.
I calibrate my screen using Color Munki. Opening Photoshop I work in sRGB. After calibration sRGB in Photoshop = monitor profile created with Colour Munki? Or should I convert it by edit / convert to profile / Colour munki monitor profile?
I downloaded from lab their colour profile. I work in sRGB and when file is ready I convert it to their profile. Is it correct workflow?
Temporarily I am using some rubbish standard Dell screen at the moment. Can it be the reason that I see pictures lighter on my monitor and much darker when printed even the screen has been calibrated?