Weird problem with paypal and invoice being different

[p_r_i_m_e]

Hi, I've just had an order where the cart shows

Original cart:
Cart #000295
Payment mode:
PayPal (paypal)
Products £169.97
Shipping £3.99
Total £173.96

and the invoice shows
Total products (tax excl.) : £184.96
Total products (tax incl.) : £184.96
Total shipping : £3.99
Total (tax excl.) : £184.96
Total (tax incl.) : £188.95

basically the amount that went to paypal is minus an item (14.99), I've looked and looked and I can't make it do it again or see a reason for it

Any Idea's ?

PS v1.3.1.1
Paypal module 2.0

Really want to get this sorted before it costs me a fortune, its not happened before or since but I don't want it to happen again!

Thanks in advance

[p_r_i_m_e]

some more info on this, it seems like the extra item (the 14,99) wasn't added by the customer and has been added at random!