Magnus,
by looking at your code snippet it seems like you haven't understand how the I2C Bus works.

Philips had a nice printed document "The I2C Bus and how to use it", it was also part in IC20 i think - however i don't know if they'll have it on the web, but there should be plenty of resources giving you an insight in this fascinating bus system.

Here a couple hints:
Transmission timing is controlled by the slave, SCL is bidirectional an must be sensed by the clock master. A slave can and will stretch clock cycles by pulling SCL low, no need for your obscure delays.
dont use too high pull-up values at high bus speeds (limit) and your bus is long and/or has many clips attached.
2K2 is a reasonable value, 10K can be too high.
when reading from a slave, the master has to supply ACK/NACK.
ACK/NACK (regarless of read/write) is supplied IMMEDIATELY after the low-high transition of the 9th clock pulse, there is no such thing as a ACK timeout - if the slave needs more time to decide wheter it should ACK or NACK it may stretch SCL after the 8th pulse.

Cheers, Roger