I wish I could tell you if I have this issue or not, but believe it or not...I have never even seen the Omnia's caller ID screen. Before I even activated mine I installed S2U2 and activated full-screen caller ID. Even in thumbnail mode the caller ID screen included in S2U2 is more finger-friendly and cooler looking than stock!
So...I can't give you a 'fix' for your problem, but I can suggest using S2U2 and get a great caller ID screen and a VERY cool lock app in the bargain!!!!
Get it here:
http://www.ac-s2.com/
The developer takes donations (freeware), and if your going to use the full-screen caller ID do yourself a favor and download S2V as well and assign all your contact pics with that!!!