Plash, I'm afraid I don't thing this can be fixed, as this would mean that BLIde performs a syntax parse before the lexical parse wich would mean a BIG performance hit (parsing would take, in the best scenarios, the triple of time).
Disable the 'complete modules hilighting' option if it is enabled to see if it that reduces this, as with this option disabled, hilighting is based on documented modules.
Disable the 'complete modules hilighting' option if it is enabled to see if it that reduces this, as with this option disabled, hilighting is based on documented modules.