Cloaking Technology

"No ship that small has a cloaking device!"
- Captain Needa, referring to the Millennium Falcon, The Empire Strikes Back

That would seem to be yet another SW technological limitation:

Size Comparison:
Millennium Falcon and Romulan "Shuttle" Runabout

Romulan Runabout decloaking -
"In the Pale Moonlight"[DS9]

Or, even better, how about the cloak from a 130 meter Romulan ship of the TOS era, installed in minutes aboard the Enterprise to cloak the ship:

Kirk and cloak beaming to the Enterprise

(The Federation phase-cloak was no larger, and though it took two Ferengi to carry a Bird-of-Prey's cloak in "The Emperor's New Cloak"[DS9], it was also smaller than a person, and later cloaked a vessel of 1,000+ meters in size.)

Pictures speak a thousand words.

(Thanks to Graham Kennedy for the DS9 cloak info.)