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Yep, I've had the same with some tins, mainly the greens, but also a matt black.
Although I prefer enamels to acrylics, the Vallejo range are very good indeed Vic. I've only used one colour so far, but it sprayed beautifully. This was from their Model Color range, which I reckon is perhaps more value for money than their airbrush ready range, as it can easily be thinned with water for air brush use, and can be used for brush painting.
I'm still trying to find a suitable alternative to Humbrol eneamel though, and although there are some, none are available locally.
I've just checked over the Airfix 1/48th Tornado kit which arrived yesterday, and, apart from the areas already warned about, such as the two different plastics and mis-matching upper and lower fuselage halves, the windscreen is missing!
The sprue was in a sealed poly bag, with some of the other 'solid' parts sprues (half the parts are loose in the box!), and there is no sign of the 'screen. The canopy, although still on its sprue, is badly scratched, due to rubbing against the larger sprues! I've contacted Airfix (Hornby) via their web-site service, and had an automated acknowledgement this time - just have to wait and see if I get a replacement. If not, it's going to be a tricky home-made moulding job!