Invisable Shield Problems with 3G light sensor???

[bftiedt]

I just installed one on the front of my 3g and I ahve noticed that sometimes my phone will go dim like it is supposed to during calls and other times it wont. i didnt notice this before i put it on but the phone has also bee opened right after i put it on also. i would think if i broke something to do with the light sensore it just wouldnt work at all but thats not the case sometimes the phone dims and sometimes it doesnt. i was just wondering if anyone else has had a problem like this or not before and the shield was to blame. Thanks a lot guys

[debo]

i have invisible shield with no problems